diff --git a/browser/actors/ContextMenuChild.jsm b/browser/actors/ContextMenuChild.jsm
index 02c99eebedbd..3e3498c12925 100644
--- a/browser/actors/ContextMenuChild.jsm
+++ b/browser/actors/ContextMenuChild.jsm
@@ -695,15 +695,13 @@ class ContextMenuChild extends ActorChild {
 
     let node = aEvent.composedTarget;
 
-    // Set the node to containing <video>/<audio>/<embed>/<object> if the node
-    // is in the videocontrols/pluginProblem UA Widget.
+    // Set the node to containing <video>/<audio> if the node
+    // is in the videocontrols UA Widget.
     if (this.content.ShadowRoot) {
       let n = node;
       while (n) {
         if (n instanceof this.content.ShadowRoot) {
-          if (n.host instanceof this.content.HTMLMediaElement ||
-              n.host instanceof this.content.HTMLEmbedElement ||
-              n.host instanceof this.content.HTMLObjectElement) {
+          if (n.host instanceof this.content.HTMLMediaElement) {
             node = n.host;
             break;
           }
diff --git a/browser/actors/PluginChild.jsm b/browser/actors/PluginChild.jsm
index 399b6dedb67a..cff82240b5d3 100644
--- a/browser/actors/PluginChild.jsm
+++ b/browser/actors/PluginChild.jsm
@@ -121,12 +121,8 @@ class PluginChild extends ActorChild {
   }
 
   getPluginUI(plugin, anonid) {
-    if (plugin.openOrClosedShadowRoot &&
-        plugin.openOrClosedShadowRoot.isUAWidget()) {
-      return plugin.openOrClosedShadowRoot.getElementById(anonid);
-    }
     return plugin.ownerDocument.
-      getAnonymousElementByAttribute(plugin, "anonid", anonid);
+           getAnonymousElementByAttribute(plugin, "anonid", anonid);
   }
 
   _getPluginInfo(pluginElement) {
@@ -636,8 +632,7 @@ class PluginChild extends ActorChild {
     let overlay = this.getPluginUI(plugin, "main");
     // Have to check that the target is not the link to update the plugin
     if (!(ChromeUtils.getClassName(event.originalTarget) === "HTMLAnchorElement") &&
-        event.originalTarget.getAttribute("anonid") != "closeIcon" &&
-        event.originalTarget.id != "closeIcon" &&
+        (event.originalTarget.getAttribute("anonid") != "closeIcon") &&
         !overlay.hasAttribute("dismissed") &&
         event.button == 0 &&
         event.isTrusted) {
diff --git a/browser/base/content/browser-plugins.js b/browser/base/content/browser-plugins.js
index d6836a51e99a..484234eed32e 100644
--- a/browser/base/content/browser-plugins.js
+++ b/browser/base/content/browser-plugins.js
@@ -445,7 +445,7 @@ var gPluginHandler = {
 
     // Configure the notification bar
     let priority = notificationBox.PRIORITY_WARNING_MEDIUM;
-    let iconURL = "chrome://global/skin/plugins/pluginGeneric.svg";
+    let iconURL = "chrome://mozapps/skin/plugins/pluginGeneric.svg";
     let reloadLabel = gNavigatorBundle.getString("crashedpluginsMessage.reloadButton.label");
     let reloadKey   = gNavigatorBundle.getString("crashedpluginsMessage.reloadButton.accesskey");
 
diff --git a/browser/base/content/test/plugins/browser.ini b/browser/base/content/test/plugins/browser.ini
index b5a17f4e5fbb..52966272d9bd 100644
--- a/browser/base/content/test/plugins/browser.ini
+++ b/browser/base/content/test/plugins/browser.ini
@@ -1,5 +1,4 @@
 [DEFAULT]
-prefs = dom.ua_widget.enabled=true
 support-files =
   blocklist_proxy.js
   blockNoPlugins.xml
diff --git a/browser/base/content/test/plugins/browser_CTP_crashreporting.js b/browser/base/content/test/plugins/browser_CTP_crashreporting.js
index dc2c40c10976..56aaf2e434f8 100644
--- a/browser/base/content/test/plugins/browser_CTP_crashreporting.js
+++ b/browser/base/content/test/plugins/browser_CTP_crashreporting.js
@@ -96,8 +96,10 @@ add_task(async function() {
       } catch (e) {
       }
 
-      let getUI = (id) => {
-        return plugin.openOrClosedShadowRoot.getElementById(id);
+      let doc = plugin.ownerDocument;
+
+      let getUI = (anonid) => {
+        return doc.getAnonymousElementByAttribute(plugin, "anonid", anonid);
       };
 
       // Now wait until the plugin crash report UI shows itself, which is
diff --git a/browser/base/content/test/plugins/browser_CTP_hide_overlay.js b/browser/base/content/test/plugins/browser_CTP_hide_overlay.js
index 620fbb4ee800..797a668ec697 100644
--- a/browser/base/content/test/plugins/browser_CTP_hide_overlay.js
+++ b/browser/base/content/test/plugins/browser_CTP_hide_overlay.js
@@ -33,8 +33,8 @@ add_task(async function() {
   await ContentTask.spawn(gBrowser.selectedBrowser, null, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    let overlay = plugin.openOrClosedShadowRoot.getElementById("main");
-    let closeIcon = plugin.openOrClosedShadowRoot.getElementById("closeIcon");
+    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
+    let closeIcon = doc.getAnonymousElementByAttribute(plugin, "anonid", "closeIcon");
     let bounds = closeIcon.getBoundingClientRect();
     let left = (bounds.left + bounds.right) / 2;
     let top = (bounds.top + bounds.bottom) / 2;
@@ -59,8 +59,8 @@ add_task(async function() {
   await ContentTask.spawn(gBrowser.selectedBrowser, null, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    let overlay = plugin.openOrClosedShadowRoot.getElementById("main");
-    let closeIcon = plugin.openOrClosedShadowRoot.getElementById("closeIcon");
+    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
+    let closeIcon = doc.getAnonymousElementByAttribute(plugin, "anonid", "closeIcon");
     let closeIconBounds = closeIcon.getBoundingClientRect();
     let overlayBounds = overlay.getBoundingClientRect();
     let overlayLeft = (overlayBounds.left + overlayBounds.right) / 2;
diff --git a/browser/base/content/test/plugins/browser_CTP_iframe.js b/browser/base/content/test/plugins/browser_CTP_iframe.js
index 108cd610753e..ecd7ab7361d1 100644
--- a/browser/base/content/test/plugins/browser_CTP_iframe.js
+++ b/browser/base/content/test/plugins/browser_CTP_iframe.js
@@ -29,11 +29,11 @@ add_task(async function() {
     let frame = content.document.getElementById("frame");
     let doc = frame.contentDocument;
     let plugin = doc.getElementById("test");
-    let overlay = plugin.openOrClosedShadowRoot.getElementById("main");
+    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
     Assert.ok(plugin && overlay.classList.contains("visible"),
       "Test 1, Plugin overlay should exist, not be hidden");
 
-    let closeIcon = plugin.openOrClosedShadowRoot.getElementById("closeIcon");
+    let closeIcon = doc.getAnonymousElementByAttribute(plugin, "anonid", "closeIcon");
     let bounds = closeIcon.getBoundingClientRect();
     let left = (bounds.left + bounds.right) / 2;
     let top = (bounds.top + bounds.bottom) / 2;
diff --git a/browser/base/content/test/plugins/browser_CTP_outsideScrollArea.js b/browser/base/content/test/plugins/browser_CTP_outsideScrollArea.js
index 4959a614f687..2e7b83bc0fd9 100644
--- a/browser/base/content/test/plugins/browser_CTP_outsideScrollArea.js
+++ b/browser/base/content/test/plugins/browser_CTP_outsideScrollArea.js
@@ -55,7 +55,8 @@ add_task(async function() {
 
   await ContentTask.spawn(gTestBrowser, {}, async function() {
     let plugin = content.document.getElementById("test");
-    let overlay = plugin.openOrClosedShadowRoot.getElementById("main");
+    let doc = content.document;
+    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
     Assert.ok(overlay && overlay.classList.contains("visible") &&
               overlay.getAttribute("sizing") != "blank",
               "Test 2, overlay should be visible.");
@@ -84,7 +85,8 @@ add_task(async function() {
 
   await ContentTask.spawn(gTestBrowser, null, async function() {
     let plugin = content.document.getElementById("test");
-    let overlay = plugin.openOrClosedShadowRoot.getElementById("main");
+    let doc = content.document;
+    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
     Assert.ok(overlay && overlay.classList.contains("visible") &&
               overlay.getAttribute("sizing") != "blank",
               "Test 3, overlay should be visible.");
@@ -112,7 +114,8 @@ add_task(async function() {
   await promisePopupNotification("click-to-play-plugins");
   await ContentTask.spawn(gTestBrowser, null, async function() {
     let plugin = content.document.getElementById("test");
-    let overlay = plugin.openOrClosedShadowRoot.getElementById("main");
+    let doc = content.document;
+    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
     Assert.ok(!overlay || overlay.getAttribute("sizing") == "blank",
       "Test 4, overlay should be blank.");
   });
diff --git a/browser/base/content/test/plugins/browser_CTP_overlay_styles.js b/browser/base/content/test/plugins/browser_CTP_overlay_styles.js
index fe0aceeeeb06..25b3331f5f8d 100644
--- a/browser/base/content/test/plugins/browser_CTP_overlay_styles.js
+++ b/browser/base/content/test/plugins/browser_CTP_overlay_styles.js
@@ -75,7 +75,7 @@ add_task(async function() {
 
     for (let testcaseId of Object.keys(testcases)) {
       let plugin = doc.querySelector(`#${testcaseId} > object`);
-      let overlay = plugin.openOrClosedShadowRoot.getElementById("main");
+      let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
       Assert.ok(overlay, `overlay exists in ${testcaseId}`);
 
       let expectations = testcases[testcaseId];
diff --git a/browser/base/content/test/plugins/browser_CTP_resize.js b/browser/base/content/test/plugins/browser_CTP_resize.js
index 455b0ba89cfa..90745a166512 100644
--- a/browser/base/content/test/plugins/browser_CTP_resize.js
+++ b/browser/base/content/test/plugins/browser_CTP_resize.js
@@ -45,7 +45,7 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, null, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    let overlay = plugin.openOrClosedShadowRoot.getElementById("main");
+    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
     Assert.ok(!overlay || overlay.getAttribute("sizing") == "blank",
       "Test 2, overlay should be blank.");
   });
@@ -63,7 +63,7 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, null, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    let overlay = plugin.openOrClosedShadowRoot.getElementById("main");
+    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
     Assert.ok(!overlay || overlay.getAttribute("sizing") == "blank",
       "Test 3, overlay should be blank.");
   });
@@ -83,7 +83,7 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, null, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    let overlay = plugin.openOrClosedShadowRoot.getElementById("main");
+    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
     Assert.ok(overlay && overlay.getAttribute("sizing") != "blank",
       "Test 4, overlay should be visible.");
   });
@@ -103,7 +103,7 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, null, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    let overlay = plugin.openOrClosedShadowRoot.getElementById("main");
+    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
     Assert.ok(!overlay || overlay.getAttribute("sizing") == "blank",
       "Test 5, overlay should be blank.");
   });
@@ -123,7 +123,7 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, null, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    let overlay = plugin.openOrClosedShadowRoot.getElementById("main");
+    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
     Assert.ok(overlay && overlay.getAttribute("sizing") != "blank",
       "Test 6, overlay should be visible.");
   });
diff --git a/browser/base/content/test/plugins/browser_CTP_shouldShowOverlay.js b/browser/base/content/test/plugins/browser_CTP_shouldShowOverlay.js
index 0ff7bcc64cc6..660e3d5ae37a 100644
--- a/browser/base/content/test/plugins/browser_CTP_shouldShowOverlay.js
+++ b/browser/base/content/test/plugins/browser_CTP_shouldShowOverlay.js
@@ -51,7 +51,7 @@ add_task(async function() {
       let plugin = testcase.querySelector("object");
       Assert.ok(plugin, `plugin exists in ${testcase.id}`);
 
-      let overlay = plugin.openOrClosedShadowRoot.getElementById("main");
+      let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
       Assert.ok(overlay, `overlay exists in ${testcase.id}`);
 
       let expectedVisibility = (testcase.getAttribute("shouldshow") == "true");
diff --git a/browser/base/content/test/plugins/browser_CTP_zoom.js b/browser/base/content/test/plugins/browser_CTP_zoom.js
index 455e06bd248a..afe7cd0bd471 100644
--- a/browser/base/content/test/plugins/browser_CTP_zoom.js
+++ b/browser/base/content/test/plugins/browser_CTP_zoom.js
@@ -52,7 +52,7 @@ add_task(async function() {
     await ContentTask.spawn(gTestBrowser, { count }, async function(args) {
       let doc = content.document;
       let plugin = doc.getElementById("test");
-      let overlay = plugin.openOrClosedShadowRoot.getElementById("main");
+      let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
       Assert.ok(overlay && overlay.classList.contains("visible"),
         "Overlay should be visible for zoom change count " + args.count);
     });
diff --git a/browser/base/content/test/plugins/browser_blocking.js b/browser/base/content/test/plugins/browser_blocking.js
index df0c9d7ee613..5819e0d2086c 100644
--- a/browser/base/content/test/plugins/browser_blocking.js
+++ b/browser/base/content/test/plugins/browser_blocking.js
@@ -55,11 +55,11 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, null, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    let overlay = plugin.openOrClosedShadowRoot.getElementById("main");
+    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
     Assert.ok(overlay && overlay.classList.contains("visible"),
       "Test 18a, Plugin overlay should exist, not be hidden");
 
-    let updateLink = plugin.openOrClosedShadowRoot.getElementById("checkForUpdatesLink");
+    let updateLink = doc.getAnonymousElementByAttribute(plugin, "anonid", "checkForUpdatesLink");
     Assert.ok(updateLink.style.visibility != "hidden",
       "Test 18a, Plugin should have an update link");
   });
@@ -69,7 +69,7 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, {}, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    let updateLink = plugin.openOrClosedShadowRoot.getElementById("checkForUpdatesLink");
+    let updateLink = doc.getAnonymousElementByAttribute(plugin, "anonid", "checkForUpdatesLink");
     let bounds = updateLink.getBoundingClientRect();
     let left = (bounds.left + bounds.right) / 2;
     let top = (bounds.top + bounds.bottom) / 2;
@@ -94,7 +94,7 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, null, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    let overlay = plugin.openOrClosedShadowRoot.getElementById("main");
+    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
     Assert.ok(overlay && overlay.classList.contains("visible"),
       "Test 18b, Plugin overlay should exist, not be hidden");
   });
@@ -122,11 +122,11 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, null, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    let overlay = plugin.openOrClosedShadowRoot.getElementById("main");
+    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
     Assert.ok(overlay && overlay.classList.contains("visible"),
       "Test 18c, Plugin overlay should exist, not be hidden");
 
-    let updateLink = plugin.openOrClosedShadowRoot.getElementById("checkForUpdatesLink");
+    let updateLink = doc.getAnonymousElementByAttribute(plugin, "anonid", "checkForUpdatesLink");
     Assert.ok(updateLink && updateLink.style.display != "block",
       "Test 18c, Plugin should not have an update link");
   });
diff --git a/browser/base/content/test/plugins/browser_pluginCrashCommentAndURL.js b/browser/base/content/test/plugins/browser_pluginCrashCommentAndURL.js
index f35da4c0e98f..260b39c120be 100644
--- a/browser/base/content/test/plugins/browser_pluginCrashCommentAndURL.js
+++ b/browser/base/content/test/plugins/browser_pluginCrashCommentAndURL.js
@@ -63,10 +63,10 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, config, async function(aConfig) {
     let doc = content.document;
     let plugin = doc.getElementById("plugin");
-    let pleaseSubmit = plugin.openOrClosedShadowRoot.getElementById("pleaseSubmit");
-    let submitButton = plugin.openOrClosedShadowRoot.getElementById("submitButton");
+    let pleaseSubmit = doc.getAnonymousElementByAttribute(plugin, "anonid", "pleaseSubmit");
+    let submitButton = doc.getAnonymousElementByAttribute(plugin, "anonid", "submitButton");
     // Test that we don't send the URL when urlOptIn is false.
-    plugin.openOrClosedShadowRoot.getElementById("submitURLOptIn").checked = aConfig.urlOptIn;
+    doc.getAnonymousElementByAttribute(plugin, "anonid", "submitURLOptIn").checked = aConfig.urlOptIn;
     submitButton.click();
     Assert.equal(content.getComputedStyle(pleaseSubmit).display == "block",
       aConfig.shouldSubmissionUIBeVisible, "The crash UI should be visible");
@@ -100,11 +100,11 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, config, async function(aConfig) {
     let doc = content.document;
     let plugin = doc.getElementById("plugin");
-    let pleaseSubmit = plugin.openOrClosedShadowRoot.getElementById("pleaseSubmit");
-    let submitButton = plugin.openOrClosedShadowRoot.getElementById("submitButton");
+    let pleaseSubmit = doc.getAnonymousElementByAttribute(plugin, "anonid", "pleaseSubmit");
+    let submitButton = doc.getAnonymousElementByAttribute(plugin, "anonid", "submitButton");
     // Test that we send the URL when urlOptIn is true.
-    plugin.openOrClosedShadowRoot.getElementById("submitURLOptIn").checked = aConfig.urlOptIn;
-    plugin.openOrClosedShadowRoot.getElementById("submitComment").value = aConfig.comment;
+    doc.getAnonymousElementByAttribute(plugin, "anonid", "submitURLOptIn").checked = aConfig.urlOptIn;
+    doc.getAnonymousElementByAttribute(plugin, "anonid", "submitComment").value = aConfig.comment;
     submitButton.click();
     Assert.equal(content.getComputedStyle(pleaseSubmit).display == "block",
       aConfig.shouldSubmissionUIBeVisible, "The crash UI should be visible");
@@ -171,7 +171,7 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, config, async function(aConfig) {
     let doc = content.document;
     let plugin = doc.getElementById("plugin");
-    let pleaseSubmit = plugin.openOrClosedShadowRoot.getElementById("pleaseSubmit");
+    let pleaseSubmit = doc.getAnonymousElementByAttribute(plugin, "anonid", "pleaseSubmit");
     Assert.equal(!!pleaseSubmit && content.getComputedStyle(pleaseSubmit).display == "block",
       aConfig.shouldSubmissionUIBeVisible, "Plugin crash UI should not be visible");
   });
diff --git a/browser/base/content/test/plugins/browser_pluginCrashReportNonDeterminism.js b/browser/base/content/test/plugins/browser_pluginCrashReportNonDeterminism.js
index 79e52fa9dc02..7774b98bc5cd 100644
--- a/browser/base/content/test/plugins/browser_pluginCrashReportNonDeterminism.js
+++ b/browser/base/content/test/plugins/browser_pluginCrashReportNonDeterminism.js
@@ -59,8 +59,9 @@ function preparePlugin(browser, pluginFallbackState) {
     // state.
     let statusDiv;
     await ContentTaskUtils.waitForCondition(() => {
-      statusDiv = plugin.openOrClosedShadowRoot.getElementById("submitStatus");
-
+      statusDiv = plugin.ownerDocument
+                        .getAnonymousElementByAttribute(plugin, "anonid",
+                                                        "submitStatus");
       return statusDiv && statusDiv.getAttribute("status") == "please";
     }, "Timed out waiting for plugin to be in crash report state");
 
@@ -157,7 +158,9 @@ add_task(async function testChromeHearsPluginCrashFirst() {
     // the PluginCrashed event.
     let plugin = content.document.getElementById("plugin");
     plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    let statusDiv = plugin.openOrClosedShadowRoot.getElementById("submitStatus");
+    let statusDiv = plugin.ownerDocument
+                          .getAnonymousElementByAttribute(plugin, "anonid",
+                                                          "submitStatus");
 
     if (statusDiv.getAttribute("status") == "please") {
       Assert.ok(false, "Did not expect plugin to be in crash report mode yet.");
@@ -217,7 +220,9 @@ add_task(async function testContentHearsCrashFirst() {
     // we're not showing the plugin crash report UI.
     let plugin = content.document.getElementById("plugin");
     plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    let statusDiv = plugin.openOrClosedShadowRoot.getElementById("submitStatus");
+    let statusDiv = plugin.ownerDocument
+                          .getAnonymousElementByAttribute(plugin, "anonid",
+                                                          "submitStatus");
 
     if (statusDiv.getAttribute("status") == "please") {
       Assert.ok(false, "Did not expect plugin to be in crash report mode yet.");
@@ -250,7 +255,9 @@ add_task(async function testContentHearsCrashFirst() {
     // crash report UI now.
     let plugin = content.document.getElementById("plugin");
     plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    let statusDiv = plugin.openOrClosedShadowRoot.getElementById("submitStatus");
+    let statusDiv = plugin.ownerDocument
+                          .getAnonymousElementByAttribute(plugin, "anonid",
+                                                          "submitStatus");
 
     Assert.equal(statusDiv.getAttribute("status"), "please",
       "Should have been showing crash report UI");
diff --git a/browser/base/content/test/plugins/browser_pluginnotification.js b/browser/base/content/test/plugins/browser_pluginnotification.js
index 97aefe664b9c..1ebacb4796c5 100644
--- a/browser/base/content/test/plugins/browser_pluginnotification.js
+++ b/browser/base/content/test/plugins/browser_pluginnotification.js
@@ -90,7 +90,7 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, null, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    let bounds = plugin.openOrClosedShadowRoot.getElementById("main").getBoundingClientRect();
+    let bounds = doc.getAnonymousElementByAttribute(plugin, "anonid", "main").getBoundingClientRect();
     let left = (bounds.left + bounds.right) / 2;
     let top = (bounds.top + bounds.bottom) / 2;
     let utils = content.windowUtils;
@@ -195,7 +195,7 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, null, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    let mainBox = plugin.openOrClosedShadowRoot.getElementById("main");
+    let mainBox = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
     Assert.ok(!!mainBox, "Test 15, Plugin overlay should exist");
   });
 });
@@ -230,7 +230,7 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, null, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    let icon = plugin.openOrClosedShadowRoot.getElementById("icon");
+    let icon = doc.getAnonymousElementByAttribute(plugin, "class", "icon");
     let bounds = icon.getBoundingClientRect();
     let left = (bounds.left + bounds.right) / 2;
     let top = (bounds.top + bounds.bottom) / 2;
@@ -259,7 +259,7 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, null, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    let text = plugin.openOrClosedShadowRoot.getElementById("clickToPlay");
+    let text = doc.getAnonymousElementByAttribute(plugin, "class", "msg msgClickToPlay");
     let bounds = text.getBoundingClientRect();
     let left = (bounds.left + bounds.right) / 2;
     let top = (bounds.top + bounds.bottom) / 2;
@@ -319,14 +319,14 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, null, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    let overlay = plugin.openOrClosedShadowRoot.getElementById("main");
+    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
     Assert.ok(!!overlay, "Test 20a, Plugin overlay should exist");
   });
 
   await ContentTask.spawn(gTestBrowser, null, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    let mainBox = plugin.openOrClosedShadowRoot.getElementById("main");
+    let mainBox = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
     let overlayRect = mainBox.getBoundingClientRect();
     Assert.ok(overlayRect.width == 0 && overlayRect.height == 0,
       "Test 20a, plugin should have an overlay with 0px width and height");
@@ -351,7 +351,7 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, null, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    let mainBox = plugin.openOrClosedShadowRoot.getElementById("main");
+    let mainBox = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
     let overlayRect = mainBox.getBoundingClientRect();
     Assert.ok(overlayRect.width == 200 && overlayRect.height == 200,
       "Test 20c, plugin should have overlay dims of 200px");
@@ -383,8 +383,9 @@ add_task(async function() {
   await ContentTask.spawn(gTestBrowser, null, async function() {
     let doc = content.document;
     let plugin = doc.getElementById("test");
-    Assert.ok(!plugin.openOrClosedShadowRoot,
-      "Test 20c, CTP UA Widget Shadow Root is removed");
+    let overlayRect = doc.getAnonymousElementByAttribute(plugin, "anonid", "main").getBoundingClientRect();
+    Assert.ok(overlayRect.width == 0 && overlayRect.height == 0,
+      "Test 20c, plugin should have overlay dims of 0px");
   });
 
   clearAllPluginPermissions();
diff --git a/browser/base/content/test/plugins/browser_private_clicktoplay.js b/browser/base/content/test/plugins/browser_private_clicktoplay.js
index 6d6a75af20b5..ea0a1470b8f4 100644
--- a/browser/base/content/test/plugins/browser_private_clicktoplay.js
+++ b/browser/base/content/test/plugins/browser_private_clicktoplay.js
@@ -200,12 +200,13 @@ add_task(async function test3d() {
                                                    "Shown");
   popupNotification.reshow();
   await promiseShown;
+  let doc = gPrivateWindow.document;
   for (let item of gPrivateWindow.PopupNotifications.panel.firstElementChild.children) {
-    let allowalways = item.openOrClosedShadowRoot.getElementById("allowalways");
+    let allowalways = doc.getAnonymousElementByAttribute(item, "anonid", "allowalways");
     ok(allowalways, "Test 3d, should have list item for allow always");
-    let allownow = item.openOrClosedShadowRoot.getElementById("allownow");
+    let allownow = doc.getAnonymousElementByAttribute(item, "anonid", "allownow");
     ok(allownow, "Test 3d, should have list item for allow now");
-    let block = item.openOrClosedShadowRoot.getElementById("block");
+    let block = doc.getAnonymousElementByAttribute(item, "anonid", "block");
     ok(block, "Test 3d, should have list item for block");
 
     if (item.action.pluginName === "Test") {
diff --git a/browser/base/content/test/plugins/xbl/.eslintrc.js b/browser/base/content/test/plugins/xbl/.eslintrc.js
deleted file mode 100644
index b1c842d8a6db..000000000000
--- a/browser/base/content/test/plugins/xbl/.eslintrc.js
+++ /dev/null
@@ -1,7 +0,0 @@
-"use strict";
-
-module.exports = {
-  "extends": [
-    "plugin:mozilla/browser-test"
-  ]
-};
diff --git a/browser/base/content/test/plugins/xbl/blockNoPlugins.xml b/browser/base/content/test/plugins/xbl/blockNoPlugins.xml
deleted file mode 100644
index e4e191b37088..000000000000
--- a/browser/base/content/test/plugins/xbl/blockNoPlugins.xml
+++ /dev/null
@@ -1,7 +0,0 @@
-<?xml version="1.0"?>
-<blocklist xmlns="http://www.mozilla.org/2006/addons-blocklist" lastupdate="1336406310001">
-  <emItems>
-  </emItems>
-  <pluginItems>
-  </pluginItems>
-</blocklist>
diff --git a/browser/base/content/test/plugins/xbl/blockPluginHard.xml b/browser/base/content/test/plugins/xbl/blockPluginHard.xml
deleted file mode 100644
index 24eb5bc6fc7a..000000000000
--- a/browser/base/content/test/plugins/xbl/blockPluginHard.xml
+++ /dev/null
@@ -1,11 +0,0 @@
-<?xml version="1.0"?>
-<blocklist xmlns="http://www.mozilla.org/2006/addons-blocklist" lastupdate="1336406310000">
-  <emItems>
-  </emItems>
-  <pluginItems>
-    <pluginItem blockID="p9999">
-      <match name="filename" exp="libnptest\.so|nptest\.dll|Test\.plugin" />
-      <versionRange severity="2"></versionRange>
-    </pluginItem>
-  </pluginItems>
-</blocklist>
diff --git a/browser/base/content/test/plugins/xbl/blockPluginInfoURL.xml b/browser/base/content/test/plugins/xbl/blockPluginInfoURL.xml
deleted file mode 100644
index c16808896ecd..000000000000
--- a/browser/base/content/test/plugins/xbl/blockPluginInfoURL.xml
+++ /dev/null
@@ -1,12 +0,0 @@
-<?xml version="1.0"?>
-<blocklist xmlns="http://www.mozilla.org/2006/addons-blocklist" lastupdate="1336406310000">
-  <emItems>
-  </emItems>
-  <pluginItems>
-    <pluginItem blockID="p9999">
-      <match name="filename" exp="libnptest\.so|nptest\.dll|Test\.plugin" />
-      <versionRange severity="2"></versionRange>
-      <infoURL>http://test.url.com/</infoURL>
-    </pluginItem>
-  </pluginItems>
-</blocklist>
diff --git a/browser/base/content/test/plugins/xbl/blockPluginVulnerableNoUpdate.xml b/browser/base/content/test/plugins/xbl/blockPluginVulnerableNoUpdate.xml
deleted file mode 100644
index bf8545afee9a..000000000000
--- a/browser/base/content/test/plugins/xbl/blockPluginVulnerableNoUpdate.xml
+++ /dev/null
@@ -1,11 +0,0 @@
-<?xml version="1.0"?>
-<blocklist xmlns="http://www.mozilla.org/2006/addons-blocklist" lastupdate="1336406310000">
-  <emItems>
-  </emItems>
-  <pluginItems>
-    <pluginItem blockID="p9999">
-      <match name="filename" exp="libnptest\.so|nptest\.dll|Test\.plugin" />
-      <versionRange severity="0" vulnerabilitystatus="2"></versionRange>
-    </pluginItem>
-  </pluginItems>
-</blocklist>
diff --git a/browser/base/content/test/plugins/xbl/blockPluginVulnerableUpdatable.xml b/browser/base/content/test/plugins/xbl/blockPluginVulnerableUpdatable.xml
deleted file mode 100644
index 5545162b1b07..000000000000
--- a/browser/base/content/test/plugins/xbl/blockPluginVulnerableUpdatable.xml
+++ /dev/null
@@ -1,11 +0,0 @@
-<?xml version="1.0"?>
-<blocklist xmlns="http://www.mozilla.org/2006/addons-blocklist" lastupdate="1336406310000">
-  <emItems>
-  </emItems>
-  <pluginItems>
-    <pluginItem blockID="p9999">
-      <match name="filename" exp="libnptest\.so|nptest\.dll|Test\.plugin" />
-      <versionRange severity="0" vulnerabilitystatus="1"></versionRange>
-    </pluginItem>
-  </pluginItems>
-</blocklist>
diff --git a/browser/base/content/test/plugins/xbl/blocklist_proxy.js b/browser/base/content/test/plugins/xbl/blocklist_proxy.js
deleted file mode 100644
index 7612f075292d..000000000000
--- a/browser/base/content/test/plugins/xbl/blocklist_proxy.js
+++ /dev/null
@@ -1,69 +0,0 @@
-var Cm = Components.manager;
-
-const kBlocklistServiceUUID = "{66354bc9-7ed1-4692-ae1d-8da97d6b205e}";
-const kBlocklistServiceContractID = "@mozilla.org/extensions/blocklist;1";
-const kBlocklistServiceFactory = Cm.getClassObject(Cc[kBlocklistServiceContractID], Ci.nsIFactory);
-
-ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
-ChromeUtils.import("resource://gre/modules/Timer.jsm");
-
-SimpleTest.requestFlakyTimeout("Need to simulate blocklist calls actually taking non-0 time to return");
-
-/*
- * A lightweight blocklist proxy for the testing purposes.
- */
-var BlocklistProxy = {
-  _uuid: null,
-
-  QueryInterface: ChromeUtils.generateQI([Ci.nsIObserver,
-                                          Ci.nsIBlocklistService,
-                                          Ci.nsITimerCallback]),
-
-  init() {
-    if (!this._uuid) {
-      this._uuid =
-        Cc["@mozilla.org/uuid-generator;1"].getService(Ci.nsIUUIDGenerator)
-                                           .generateUUID();
-      Cm.nsIComponentRegistrar.registerFactory(this._uuid, "",
-                                               "@mozilla.org/extensions/blocklist;1",
-                                               this);
-    }
-  },
-
-  uninit() {
-    if (this._uuid) {
-      Cm.nsIComponentRegistrar.unregisterFactory(this._uuid, this);
-      Cm.nsIComponentRegistrar.registerFactory(Components.ID(kBlocklistServiceUUID),
-                                               "Blocklist Service",
-                                               "@mozilla.org/extensions/blocklist;1",
-                                               kBlocklistServiceFactory);
-      this._uuid = null;
-    }
-  },
-
-  notify(aTimer) {
-  },
-
-  observe(aSubject, aTopic, aData) {
-  },
-
-  async getAddonBlocklistState(aAddon, aAppVersion, aToolkitVersion) {
-    await new Promise(r => setTimeout(r, 150));
-    return 0; // STATE_NOT_BLOCKED
-  },
-
-  async getPluginBlocklistState(aPluginTag, aAppVersion, aToolkitVersion) {
-    await new Promise(r => setTimeout(r, 150));
-    return 0; // STATE_NOT_BLOCKED
-  },
-
-  async getPluginBlockURL(aPluginTag) {
-    await new Promise(r => setTimeout(r, 150));
-    return "";
-  },
-};
-
-BlocklistProxy.init();
-addEventListener("unload", () => {
-  BlocklistProxy.uninit();
-});
diff --git a/browser/base/content/test/plugins/xbl/browser.ini b/browser/base/content/test/plugins/xbl/browser.ini
deleted file mode 100644
index 4e2bcbf81658..000000000000
--- a/browser/base/content/test/plugins/xbl/browser.ini
+++ /dev/null
@@ -1,98 +0,0 @@
-[DEFAULT]
-prefs = dom.ua_widget.enabled=false
-support-files =
-  blocklist_proxy.js
-  blockNoPlugins.xml
-  blockPluginHard.xml
-  blockPluginInfoURL.xml
-  blockPluginVulnerableNoUpdate.xml
-  blockPluginVulnerableUpdatable.xml
-  browser_clearplugindata.html
-  browser_clearplugindata_noage.html
-  empty_file.html
-  ../head.js
-  plugin_add_dynamically.html
-  plugin_alternate_content.html
-  plugin_big.html
-  plugin_both.html
-  plugin_both2.html
-  plugin_bug744745.html
-  plugin_bug749455.html
-  plugin_bug787619.html
-  plugin_bug797677.html
-  plugin_bug820497.html
-  plugin_clickToPlayAllow.html
-  plugin_clickToPlayDeny.html
-  plugin_favorfallback.html
-  plugin_hidden_to_visible.html
-  plugin_iframe.html
-  plugin_outsideScrollArea.html
-  plugin_overlay_styles.html
-  plugin_simple_blank.swf
-  plugin_shouldShowOverlay.html
-  plugin_small.html
-  plugin_small_2.html
-  plugin_syncRemoved.html
-  plugin_test.html
-  plugin_test2.html
-  plugin_test3.html
-  plugin_two_types.html
-  plugin_unknown.html
-  plugin_crashCommentAndURL.html
-  plugin_zoom.html
-
-[browser_bug743421.js]
-tags = blocklist
-[browser_bug744745.js]
-[browser_bug787619.js]
-[browser_bug797677.js]
-[browser_bug812562.js]
-tags = blocklist
-[browser_bug818118.js]
-[browser_bug820497.js]
-[browser_clearplugindata.js]
-tags = blocklist
-[browser_CTP_context_menu.js]
-skip-if = toolkit == "gtk3"   # fails intermittently on Linux (bug 909342)
-tags = blocklist
-[browser_CTP_crashreporting.js]
-skip-if = !crashreporter || verify
-tags = blocklist
-[browser_CTP_drag_drop.js]
-tags = blocklist
-[browser_CTP_favorfallback.js]
-[browser_CTP_hide_overlay.js]
-tags = blocklist
-[browser_CTP_iframe.js]
-tags = blocklist
-[browser_CTP_nonplugins.js]
-skip-if = verify
-tags = blocklist
-[browser_CTP_outsideScrollArea.js]
-tags = blocklist
-[browser_CTP_overlay_styles.js]
-[browser_CTP_resize.js]
-tags = blocklist
-[browser_CTP_shouldShowOverlay.js]
-[browser_CTP_zoom.js]
-tags = blocklist
-[browser_blocking.js]
-tags = blocklist
-[browser_iterate_hidden_plugins.js]
-[browser_pluginnotification.js]
-tags = blocklist
-[browser_plugin_reloading.js]
-tags = blocklist
-[browser_blocklist_content.js]
-skip-if = !e10s
-tags = blocklist
-[browser_enable_DRM_prompt.js]
-[browser_private_browsing_eme_persistent_state.js]
-[browser_globalplugin_crashinfobar.js]
-skip-if = !crashreporter
-[browser_pluginCrashCommentAndURL.js]
-skip-if = !crashreporter
-[browser_pluginCrashReportNonDeterminism.js]
-skip-if = !crashreporter
-[browser_private_clicktoplay.js]
-[browser_subframe_access_hidden_plugins.js]
diff --git a/browser/base/content/test/plugins/xbl/browser_CTP_context_menu.js b/browser/base/content/test/plugins/xbl/browser_CTP_context_menu.js
deleted file mode 100644
index f16d29aab906..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_CTP_context_menu.js
+++ /dev/null
@@ -1,70 +0,0 @@
-/* import-globals-from ../head.js */
-
-var rootDir = getRootDirectory(gTestPath);
-const gTestRoot = rootDir.replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-
-add_task(async function() {
-  registerCleanupFunction(function() {
-    clearAllPluginPermissions();
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    Services.prefs.clearUserPref("extensions.blocklist.suppressUI");
-    gBrowser.removeCurrentTab();
-    window.focus();
-  });
-});
-
-// Test that the activate action in content menus for CTP plugins works
-add_task(async function() {
-  Services.prefs.setBoolPref("extensions.blocklist.suppressUI", true);
-
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Test Plug-in");
-  let bindingPromise = BrowserTestUtils.waitForContentEvent(gBrowser.selectedBrowser, "PluginBindingAttached", true, null, true);
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-  await promiseUpdatePluginBindings(gBrowser.selectedBrowser);
-  await bindingPromise;
-
-  let popupNotification = PopupNotifications.getNotification("click-to-play-plugins", gBrowser.selectedBrowser);
-  ok(popupNotification, "Test 1, Should have a click-to-play notification");
-
-  // check plugin state
-  let pluginInfo = await promiseForPluginInfo("test", gBrowser.selectedBrowser);
-  ok(!pluginInfo.activated, "plugin should not be activated");
-
-  // Display a context menu on the test plugin so we can test
-  // activation menu options.
-  await ContentTask.spawn(gBrowser.selectedBrowser, {}, async function() {
-    let plugin = content.document.getElementById("test");
-    let bounds = plugin.getBoundingClientRect();
-    let left = (bounds.left + bounds.right) / 2;
-    let top = (bounds.top + bounds.bottom) / 2;
-    let utils = content.windowUtils;
-    utils.sendMouseEvent("contextmenu", left, top, 2, 1, 0);
-  });
-
-  popupNotification = PopupNotifications.getNotification("click-to-play-plugins", gBrowser.selectedBrowser);
-  ok(popupNotification, "Should have a click-to-play notification");
-  ok(popupNotification.dismissed, "notification should be dismissed");
-
-  // fixes a occasional test timeout on win7 opt
-  await promiseForCondition(() => document.getElementById("context-ctp-play"));
-
-  let actMenuItem = document.getElementById("context-ctp-play");
-  ok(actMenuItem, "Should have a context menu entry for activating the plugin");
-
-  // Activate the plugin via the context menu
-  EventUtils.synthesizeMouseAtCenter(actMenuItem, {});
-
-  await promiseForCondition(() => !PopupNotifications.panel.dismissed && PopupNotifications.panel.firstElementChild);
-
-  // Activate the plugin
-  PopupNotifications.panel.firstElementChild.button.click();
-
-  // check plugin state
-  pluginInfo = await promiseForPluginInfo("test", gBrowser.selectedBrowser);
-  ok(pluginInfo.activated, "plugin should not be activated");
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_CTP_crashreporting.js b/browser/base/content/test/plugins/xbl/browser_CTP_crashreporting.js
deleted file mode 100644
index 34d57b3b0313..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_CTP_crashreporting.js
+++ /dev/null
@@ -1,234 +0,0 @@
-/* import-globals-from ../head.js */
-
-var rootDir = getRootDirectory(gTestPath);
-const gTestRoot = rootDir.replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-const SERVER_URL = "http://example.com/browser/toolkit/crashreporter/test/browser/crashreport.sjs";
-const PLUGIN_PAGE = gTestRoot + "plugin_big.html";
-const PLUGIN_SMALL_PAGE = gTestRoot + "plugin_small.html";
-
-/**
- * Takes an nsIPropertyBag and converts it into a JavaScript Object. It
- * will also convert any nsIPropertyBag's within the nsIPropertyBag
- * recursively.
- *
- * @param aBag
- *        The nsIPropertyBag to convert.
- * @return Object
- *        Keyed on the names of the nsIProperty's within the nsIPropertyBag,
- *        and mapping to their values.
- */
-function convertPropertyBag(aBag) {
-  let result = {};
-  for (let { name, value } of aBag.enumerator) {
-    if (value instanceof Ci.nsIPropertyBag) {
-      value = convertPropertyBag(value);
-    }
-    result[name] = value;
-  }
-  return result;
-}
-
-add_task(async function setup() {
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Test Plug-in");
-
-  // The test harness sets MOZ_CRASHREPORTER_NO_REPORT, which disables plugin
-  // crash reports.  This test needs them enabled.  The test also needs a mock
-  // report server, and fortunately one is already set up by toolkit/
-  // crashreporter/test/Makefile.in.  Assign its URL to MOZ_CRASHREPORTER_URL,
-  // which CrashSubmit.jsm uses as a server override.
-  let env = Cc["@mozilla.org/process/environment;1"].
-            getService(Ci.nsIEnvironment);
-  let noReport = env.get("MOZ_CRASHREPORTER_NO_REPORT");
-  let serverURL = env.get("MOZ_CRASHREPORTER_URL");
-  env.set("MOZ_CRASHREPORTER_NO_REPORT", "");
-  env.set("MOZ_CRASHREPORTER_URL", SERVER_URL);
-
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-  Services.prefs.setBoolPref("extensions.blocklist.suppressUI", true);
-
-  registerCleanupFunction(function cleanUp() {
-    clearAllPluginPermissions();
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    env.set("MOZ_CRASHREPORTER_NO_REPORT", noReport);
-    env.set("MOZ_CRASHREPORTER_URL", serverURL);
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    Services.prefs.clearUserPref("extensions.blocklist.suppressUI");
-    window.focus();
-  });
-});
-
-/**
- * Test that plugin crash submissions still work properly after
- * click-to-play activation.
- */
-add_task(async function() {
-  await BrowserTestUtils.withNewTab({
-    gBrowser,
-    url: PLUGIN_PAGE,
-  }, async function(browser) {
-    // Work around for delayed PluginBindingAttached
-    await promiseUpdatePluginBindings(browser);
-
-    let pluginInfo = await promiseForPluginInfo("test", browser);
-    ok(!pluginInfo.activated, "Plugin should not be activated");
-
-    // Simulate clicking the "Allow Always" button.
-    let notification = PopupNotifications.getNotification("click-to-play-plugins", browser);
-    await promiseForNotificationShown(notification, browser);
-    PopupNotifications.panel.firstElementChild.button.click();
-
-    // Prepare a crash report topic observer that only returns when
-    // the crash report has been successfully sent.
-    let crashReportChecker = (subject, data) => {
-      return (data == "success");
-    };
-    let crashReportPromise = TestUtils.topicObserved("crash-report-status",
-                                                     crashReportChecker);
-
-    await ContentTask.spawn(browser, null, async function() {
-      let plugin = content.document.getElementById("test");
-      plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-
-      await ContentTaskUtils.waitForCondition(() => {
-        return plugin.activated;
-      }, "Waited too long for plugin to activate.");
-
-      try {
-        Cu.waiveXrays(plugin).crash();
-      } catch (e) {
-      }
-
-      let doc = plugin.ownerDocument;
-
-      let getUI = (anonid) => {
-        return doc.getAnonymousElementByAttribute(plugin, "anonid", anonid);
-      };
-
-      // Now wait until the plugin crash report UI shows itself, which is
-      // asynchronous.
-      let statusDiv;
-
-      await ContentTaskUtils.waitForCondition(() => {
-        statusDiv = getUI("submitStatus");
-        return statusDiv.getAttribute("status") == "please";
-      }, "Waited too long for plugin to show crash report UI");
-
-      // Make sure the UI matches our expectations...
-      let style = content.getComputedStyle(getUI("pleaseSubmit"));
-      if (style.display != "block") {
-        throw new Error(`Submission UI visibility is not correct. ` +
-                        `Expected block style, got ${style.display}.`);
-      }
-
-      // Fill the crash report in with some test values that we'll test for in
-      // the parent.
-      getUI("submitComment").value = "a test comment";
-      let optIn = getUI("submitURLOptIn");
-      if (!optIn.checked) {
-        throw new Error("URL opt-in should default to true.");
-      }
-
-      // Submit the report.
-      optIn.click();
-      getUI("submitButton").click();
-
-      // And wait for the parent to say that the crash report was submitted
-      // successfully. This can take time on debug builds.
-      await ContentTaskUtils.waitForCondition(() => {
-        return statusDiv.getAttribute("status") == "success";
-      }, "Timed out waiting for plugin binding to be in success state",
-      100, 200);
-    });
-
-    let [subject ] = await crashReportPromise;
-
-    ok(subject instanceof Ci.nsIPropertyBag,
-       "The crash report subject should be an nsIPropertyBag.");
-
-    let crashData = convertPropertyBag(subject);
-    ok(crashData.serverCrashID, "Should have a serverCrashID set.");
-
-    // Remove the submitted report file after ensuring it exists.
-    let file = Cc["@mozilla.org/file/local;1"]
-                 .createInstance(Ci.nsIFile);
-    file.initWithPath(Services.crashmanager._submittedDumpsDir);
-    file.append(crashData.serverCrashID + ".txt");
-    ok(file.exists(), "Submitted report file should exist");
-    file.remove(false);
-
-    ok(crashData.extra, "Extra data should exist");
-    is(crashData.extra.PluginUserComment, "a test comment",
-       "Comment in extra data should match comment in textbox");
-
-    is(crashData.extra.PluginContentURL, undefined,
-       "URL should be absent from extra data when opt-in not checked");
-  });
-});
-
-/**
- * Test that plugin crash submissions still work properly after
- * click-to-play with the notification bar.
- */
-add_task(async function() {
-  await BrowserTestUtils.withNewTab({
-    gBrowser,
-    url: PLUGIN_SMALL_PAGE,
-  }, async function(browser) {
-    // Work around for delayed PluginBindingAttached
-    await promiseUpdatePluginBindings(browser);
-
-    let pluginInfo = await promiseForPluginInfo("test", browser);
-    ok(pluginInfo.activated, "Plugin should be activated from previous test");
-
-    // Prepare a crash report topic observer that only returns when
-    // the crash report has been successfully sent.
-    let crashReportChecker = (subject, data) => {
-      return (data == "success");
-    };
-    let crashReportPromise = TestUtils.topicObserved("crash-report-status",
-                                                     crashReportChecker);
-
-    await ContentTask.spawn(browser, null, async function() {
-      let plugin = content.document.getElementById("test");
-      plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-
-      await ContentTaskUtils.waitForCondition(() => {
-        return plugin.activated;
-      }, "Waited too long for plugin to activate.");
-
-      try {
-        Cu.waiveXrays(plugin).crash();
-      } catch (e) {}
-    });
-
-    // Wait for the notification bar to be displayed.
-    let notification = await waitForNotificationBar("plugin-crashed", browser);
-
-    // Then click the button to submit the crash report.
-    let buttons = notification.querySelectorAll(".notification-button");
-    is(buttons.length, 2, "Should have two buttons.");
-
-    // The "Submit Crash Report" button should be the second one.
-    let submitButton = buttons[1];
-    submitButton.click();
-
-    let [subject ] = await crashReportPromise;
-
-    ok(subject instanceof Ci.nsIPropertyBag,
-       "The crash report subject should be an nsIPropertyBag.");
-
-    let crashData = convertPropertyBag(subject);
-    ok(crashData.serverCrashID, "Should have a serverCrashID set.");
-
-    // Remove the submitted report file after ensuring it exists.
-    let file = Cc["@mozilla.org/file/local;1"]
-                 .createInstance(Ci.nsIFile);
-    file.initWithPath(Services.crashmanager._submittedDumpsDir);
-    file.append(crashData.serverCrashID + ".txt");
-    ok(file.exists(), "Submitted report file should exist");
-    file.remove(false);
-
-    is(crashData.extra.PluginContentURL, undefined,
-       "URL should be absent from extra data when opt-in not checked");
-  });
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_CTP_drag_drop.js b/browser/base/content/test/plugins/xbl/browser_CTP_drag_drop.js
deleted file mode 100644
index f504c30f4732..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_CTP_drag_drop.js
+++ /dev/null
@@ -1,97 +0,0 @@
-/* import-globals-from ../head.js */
-
-var gTestRoot = getRootDirectory(gTestPath).replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gNewWindow = null;
-
-add_task(async function() {
-  registerCleanupFunction(function() {
-    clearAllPluginPermissions();
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    Services.prefs.clearUserPref("extensions.blocklist.suppressUI");
-    gNewWindow.close();
-    gNewWindow = null;
-    window.focus();
-  });
-});
-
-add_task(async function() {
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-  Services.prefs.setBoolPref("extensions.blocklist.suppressUI", true);
-
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Test Plug-in");
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gBrowser.selectedBrowser);
-
-  await promisePopupNotification("click-to-play-plugins");
-});
-
-add_task(async function() {
-  gNewWindow = gBrowser.replaceTabWithWindow(gBrowser.selectedTab);
-
-  // XXX technically can't load fire before we get this call???
-  await BrowserTestUtils.waitForEvent(gNewWindow, "load", true);
-
-  await promisePopupNotification("click-to-play-plugins", gNewWindow.gBrowser.selectedBrowser);
-
-  ok(PopupNotifications.getNotification("click-to-play-plugins", gNewWindow.gBrowser.selectedBrowser), "Should have a click-to-play notification in the tab in the new window");
-  ok(!PopupNotifications.getNotification("click-to-play-plugins", gBrowser.selectedBrowser), "Should not have a click-to-play notification in the old window now");
-});
-
-add_task(async function() {
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-  gBrowser.swapBrowsersAndCloseOther(gBrowser.selectedTab, gNewWindow.gBrowser.selectedTab);
-
-  await promisePopupNotification("click-to-play-plugins", gBrowser.selectedBrowser);
-
-  ok(PopupNotifications.getNotification("click-to-play-plugins", gBrowser.selectedBrowser), "Should have a click-to-play notification in the initial tab again");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gBrowser.selectedBrowser);
-});
-
-add_task(async function() {
-  await promisePopupNotification("click-to-play-plugins");
-
-  gNewWindow = gBrowser.replaceTabWithWindow(gBrowser.selectedTab);
-
-  await promiseWaitForFocus(gNewWindow);
-
-  await promisePopupNotification("click-to-play-plugins", gNewWindow.gBrowser.selectedBrowser);
-});
-
-add_task(async function() {
-  ok(PopupNotifications.getNotification("click-to-play-plugins", gNewWindow.gBrowser.selectedBrowser), "Should have a click-to-play notification in the tab in the new window");
-  ok(!PopupNotifications.getNotification("click-to-play-plugins", gBrowser.selectedBrowser), "Should not have a click-to-play notification in the old window now");
-
-  let pluginInfo = await promiseForPluginInfo("test", gNewWindow.gBrowser.selectedBrowser);
-  ok(!pluginInfo.activated, "plugin should not be activated");
-
-  await ContentTask.spawn(gNewWindow.gBrowser.selectedBrowser, {}, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let bounds = plugin.getBoundingClientRect();
-    let left = (bounds.left + bounds.right) / 2;
-    let top = (bounds.top + bounds.bottom) / 2;
-    let utils = content.windowUtils;
-    utils.sendMouseEvent("mousedown", left, top, 0, 1, 0, false, 0, 0);
-    utils.sendMouseEvent("mouseup", left, top, 0, 1, 0, false, 0, 0);
-  });
-
-  let condition = () => !PopupNotifications.getNotification("click-to-play-plugins", gNewWindow.gBrowser.selectedBrowser).dismissed && gNewWindow.PopupNotifications.panel.firstElementChild;
-  await promiseForCondition(condition);
-});
-
-add_task(async function() {
-  // Click the activate button on doorhanger to make sure it works
-  gNewWindow.PopupNotifications.panel.firstElementChild.button.click();
-
-  let pluginInfo = await promiseForPluginInfo("test", gNewWindow.gBrowser.selectedBrowser);
-  ok(pluginInfo.activated, "plugin should be activated");
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_CTP_favorfallback.js b/browser/base/content/test/plugins/xbl/browser_CTP_favorfallback.js
deleted file mode 100644
index 9c2fc2ebb0ca..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_CTP_favorfallback.js
+++ /dev/null
@@ -1,86 +0,0 @@
-/* import-globals-from ../head.js */
-
-var rootDir = getRootDirectory(gTestPath);
-const gTestRoot = rootDir.replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gPluginHost = Cc["@mozilla.org/plugin/host;1"].getService(Ci.nsIPluginHost);
-
-add_task(async function() {
-  registerCleanupFunction(function() {
-    clearAllPluginPermissions();
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Shockwave Flash");
-    Services.prefs.clearUserPref("plugins.favorfallback.mode");
-    Services.prefs.clearUserPref("plugins.favorfallback.rules");
-  });
-});
-
-add_task(async function() {
-  Services.prefs.setCharPref("plugins.favorfallback.mode", "follow-ctp");
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Shockwave Flash");
-});
-
-/* The expected behavior of each testcase is documented with its markup
- * in plugin_favorfallback.html.
- *
- *  - "name" is the name of the testcase in the test file.
- *  - "rule" is how the plugins.favorfallback.rules must be configured
- *           for this testcase.
- */
-const testcases = [
-  {
-    name: "video",
-    rule: "video",
-  },
-
-  {
-    name: "nosrc",
-    rule: "nosrc",
-  },
-
-  {
-    name: "embed",
-    rule: "embed,true",
-  },
-
-  {
-    name: "adobelink",
-    rule: "adobelink,true",
-  },
-
-  {
-    name: "installinstructions",
-    rule: "installinstructions,true",
-  },
-
-];
-
-add_task(async function() {
-  for (let testcase of Object.values(testcases)) {
-    info(`Running testcase ${testcase.name}`);
-
-    Services.prefs.setCharPref("plugins.favorfallback.rules", testcase.rule);
-
-    let tab = await BrowserTestUtils.openNewForegroundTab(
-      gBrowser,
-      `${gTestRoot}plugin_favorfallback.html?testcase=${testcase.name}`
-    );
-
-    await ContentTask.spawn(tab.linkedBrowser, testcase.name, async function testPlugins(name) {
-      let testcaseDiv = content.document.getElementById(`testcase_${name}`);
-      let ctpPlugins = testcaseDiv.querySelectorAll(".expected_ctp");
-
-      for (let ctpPlugin of ctpPlugins) {
-        ok(ctpPlugin instanceof Ci.nsIObjectLoadingContent, "This is a plugin object");
-        is(ctpPlugin.pluginFallbackType, Ci.nsIObjectLoadingContent.PLUGIN_CLICK_TO_PLAY, "Plugin is CTP");
-      }
-
-      let fallbackPlugins = testcaseDiv.querySelectorAll(".expected_fallback");
-
-      for (let fallbackPlugin of fallbackPlugins) {
-        ok(fallbackPlugin instanceof Ci.nsIObjectLoadingContent, "This is a plugin object");
-        is(fallbackPlugin.pluginFallbackType, Ci.nsIObjectLoadingContent.PLUGIN_ALTERNATE, "Plugin fallback content was used");
-      }
-    });
-
-    BrowserTestUtils.removeTab(tab);
-  }
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_CTP_hide_overlay.js b/browser/base/content/test/plugins/xbl/browser_CTP_hide_overlay.js
deleted file mode 100644
index 0ada18652578..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_CTP_hide_overlay.js
+++ /dev/null
@@ -1,88 +0,0 @@
-/* import-globals-from ../head.js */
-
-var rootDir = getRootDirectory(gTestPath);
-const gTestRoot = rootDir.replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gPluginHost = Cc["@mozilla.org/plugin/host;1"].getService(Ci.nsIPluginHost);
-
-add_task(async function() {
-  registerCleanupFunction(function() {
-    clearAllPluginPermissions();
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    Services.prefs.clearUserPref("extensions.blocklist.suppressUI");
-    gBrowser.removeCurrentTab();
-    window.focus();
-  });
-});
-
-add_task(async function() {
-  Services.prefs.setBoolPref("extensions.blocklist.suppressUI", true);
-
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Test Plug-in");
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Second Test Plug-in");
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gBrowser.selectedBrowser);
-
-  // Tests that the overlay can be hidden for plugins using the close icon.
-  await ContentTask.spawn(gBrowser.selectedBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-    let closeIcon = doc.getAnonymousElementByAttribute(plugin, "anonid", "closeIcon");
-    let bounds = closeIcon.getBoundingClientRect();
-    let left = (bounds.left + bounds.right) / 2;
-    let top = (bounds.top + bounds.bottom) / 2;
-    let utils = content.windowUtils;
-    utils.sendMouseEvent("mousedown", left, top, 0, 1, 0, false, 0, 0);
-    utils.sendMouseEvent("mouseup", left, top, 0, 1, 0, false, 0, 0);
-
-    Assert.ok(!overlay.classList.contains("visible"), "overlay should be hidden.");
-  });
-});
-
-// Test that the overlay cannot be interacted with after the user closes the overlay
-add_task(async function() {
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Test Plug-in");
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Second Test Plug-in");
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gBrowser.selectedBrowser);
-
-  await ContentTask.spawn(gBrowser.selectedBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-    let closeIcon = doc.getAnonymousElementByAttribute(plugin, "anonid", "closeIcon");
-    let closeIconBounds = closeIcon.getBoundingClientRect();
-    let overlayBounds = overlay.getBoundingClientRect();
-    let overlayLeft = (overlayBounds.left + overlayBounds.right) / 2;
-    let overlayTop = (overlayBounds.left + overlayBounds.right) / 2 ;
-    let closeIconLeft = (closeIconBounds.left + closeIconBounds.right) / 2;
-    let closeIconTop = (closeIconBounds.top + closeIconBounds.bottom) / 2;
-    let utils = content.windowUtils;
-    // Simulate clicking on the close icon.
-    utils.sendMouseEvent("mousedown", closeIconLeft, closeIconTop, 0, 1, 0, false, 0, 0);
-    utils.sendMouseEvent("mouseup", closeIconLeft, closeIconTop, 0, 1, 0, false, 0, 0);
-
-    // Simulate clicking on the overlay.
-    utils.sendMouseEvent("mousedown", overlayLeft, overlayTop, 0, 1, 0, false, 0, 0);
-    utils.sendMouseEvent("mouseup", overlayLeft, overlayTop, 0, 1, 0, false, 0, 0);
-
-    Assert.ok(overlay.hasAttribute("dismissed") && !overlay.classList.contains("visible"),
-      "Overlay should be hidden");
-  });
-
-  let notification = PopupNotifications.getNotification("click-to-play-plugins");
-
-  ok(notification.dismissed, "No notification should be shown");
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_CTP_iframe.js b/browser/base/content/test/plugins/xbl/browser_CTP_iframe.js
deleted file mode 100644
index 6c9414615bee..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_CTP_iframe.js
+++ /dev/null
@@ -1,49 +0,0 @@
-/* import-globals-from ../head.js */
-
-var rootDir = getRootDirectory(gTestPath);
-const gTestRoot = rootDir.replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-
-add_task(async function() {
-  registerCleanupFunction(function() {
-    clearAllPluginPermissions();
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    Services.prefs.clearUserPref("extensions.blocklist.suppressUI");
-    gBrowser.removeCurrentTab();
-    window.focus();
-  });
-});
-
-add_task(async function() {
-  Services.prefs.setBoolPref("extensions.blocklist.suppressUI", true);
-
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Test Plug-in");
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_iframe.html");
-
-  // Tests that the overlays are visible and actionable if the plugin is in an iframe.
-
-  await ContentTask.spawn(gBrowser.selectedBrowser, null, async function() {
-    let frame = content.document.getElementById("frame");
-    let doc = frame.contentDocument;
-    let plugin = doc.getElementById("test");
-    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-    Assert.ok(plugin && overlay.classList.contains("visible"),
-      "Test 1, Plugin overlay should exist, not be hidden");
-
-    let closeIcon = doc.getAnonymousElementByAttribute(plugin, "anonid", "closeIcon");
-    let bounds = closeIcon.getBoundingClientRect();
-    let left = (bounds.left + bounds.right) / 2;
-    let top = (bounds.top + bounds.bottom) / 2;
-    let utils = doc.defaultView.windowUtils;
-    utils.sendMouseEvent("mousedown", left, top, 0, 1, 0, false, 0, 0);
-    utils.sendMouseEvent("mouseup", left, top, 0, 1, 0, false, 0, 0);
-    Assert.ok(!overlay.classList.contains("visible"),
-      "Test 1, Plugin overlay should exist, be hidden");
-  });
-});
-
diff --git a/browser/base/content/test/plugins/xbl/browser_CTP_nonplugins.js b/browser/base/content/test/plugins/xbl/browser_CTP_nonplugins.js
deleted file mode 100644
index 5c1427dff858..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_CTP_nonplugins.js
+++ /dev/null
@@ -1,60 +0,0 @@
-/* import-globals-from ../head.js */
-
-var rootDir = getRootDirectory(gTestPath);
-const gTestRoot = rootDir.replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gPluginHost = Cc["@mozilla.org/plugin/host;1"].getService(Ci.nsIPluginHost);
-
-add_task(async function() {
-  registerCleanupFunction(function() {
-    clearAllPluginPermissions();
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    Services.prefs.clearUserPref("extensions.blocklist.suppressUI");
-    gBrowser.removeCurrentTab();
-    window.focus();
-  });
-});
-
-add_task(async function() {
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-  Services.prefs.setBoolPref("extensions.blocklist.suppressUI", true);
-
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_DISABLED, "Test Plug-in");
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_two_types.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gBrowser.selectedBrowser);
-
-  // Test that the click-to-play notification is not shown for non-plugin object elements
-  let popupNotification = PopupNotifications.getNotification("click-to-play-plugins", gBrowser.selectedBrowser);
-  ok(popupNotification, "Test 1, Should have a click-to-play notification");
-
-  let pluginRemovedPromise = BrowserTestUtils.waitForContentEvent(gBrowser.selectedBrowser, "PluginRemoved", true, null, true);
-  await ContentTask.spawn(gBrowser.selectedBrowser, {}, async function() {
-    let plugin = content.document.getElementById("secondtestA");
-    plugin.remove();
-    plugin = content.document.getElementById("secondtestB");
-    plugin.remove();
-
-    let image = content.document.createElement("object");
-    image.type = "image/png";
-    image.data = "moz.png";
-    content.document.body.appendChild(image);
-  });
-  await pluginRemovedPromise;
-
-  popupNotification = PopupNotifications.getNotification("click-to-play-plugins", gBrowser.selectedBrowser);
-  ok(popupNotification, "Test 2, Should have a click-to-play notification");
-
-  await ContentTask.spawn(gBrowser.selectedBrowser, {}, async function() {
-    let plugin = content.document.getElementById("test");
-    plugin.remove();
-  });
-
-  popupNotification = PopupNotifications.getNotification("click-to-play-plugins", gBrowser.selectedBrowser);
-  ok(popupNotification, "Test 3, Should still have a click-to-play notification");
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_CTP_outsideScrollArea.js b/browser/base/content/test/plugins/xbl/browser_CTP_outsideScrollArea.js
deleted file mode 100644
index f6c700ffe22f..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_CTP_outsideScrollArea.js
+++ /dev/null
@@ -1,124 +0,0 @@
-/* import-globals-from ../head.js */
-
-var rootDir = getRootDirectory(gTestPath);
-const gTestRoot = rootDir.replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gTestBrowser = null;
-var gPluginHost = Cc["@mozilla.org/plugin/host;1"].getService(Ci.nsIPluginHost);
-
-add_task(async function() {
-  registerCleanupFunction(function() {
-    clearAllPluginPermissions();
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    Services.prefs.clearUserPref("extensions.blocklist.suppressUI");
-    gBrowser.removeCurrentTab();
-    window.focus();
-    gTestBrowser = null;
-  });
-});
-
-add_task(async function() {
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-  Services.prefs.setBoolPref("extensions.blocklist.suppressUI", true);
-
-  let newTab = BrowserTestUtils.addTab(gBrowser);
-  gBrowser.selectedTab = newTab;
-  gTestBrowser = gBrowser.selectedBrowser;
-
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Test Plug-in");
-
-  let popupNotification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(!popupNotification, "Test 1, Should not have a click-to-play notification");
-});
-
-// Test that the click-to-play overlay is not hidden for elements
-// partially or fully outside the viewport.
-
-add_task(async function() {
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_outsideScrollArea.html");
-
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let doc = content.document;
-    let p = doc.createElement("embed");
-
-    p.setAttribute("id", "test");
-    p.setAttribute("type", "application/x-test");
-    p.style.left = "0";
-    p.style.bottom = "200px";
-
-    doc.getElementById("container").appendChild(p);
-  });
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  await promisePopupNotification("click-to-play-plugins");
-
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let plugin = content.document.getElementById("test");
-    let doc = content.document;
-    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-    Assert.ok(overlay && overlay.classList.contains("visible") &&
-              overlay.getAttribute("sizing") != "blank",
-              "Test 2, overlay should be visible.");
-  });
-});
-
-add_task(async function() {
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_outsideScrollArea.html");
-
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let doc = content.document;
-    let p = doc.createElement("embed");
-
-    p.setAttribute("id", "test");
-    p.setAttribute("type", "application/x-test");
-    p.style.left = "0";
-    p.style.bottom = "-410px";
-
-    doc.getElementById("container").appendChild(p);
-  });
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  await promisePopupNotification("click-to-play-plugins");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let plugin = content.document.getElementById("test");
-    let doc = content.document;
-    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-    Assert.ok(overlay && overlay.classList.contains("visible") &&
-              overlay.getAttribute("sizing") != "blank",
-              "Test 3, overlay should be visible.");
-  });
-});
-
-add_task(async function() {
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_outsideScrollArea.html");
-
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let doc = content.document;
-    let p = doc.createElement("embed");
-
-    p.setAttribute("id", "test");
-    p.setAttribute("type", "application/x-test");
-    p.style.left = "-600px";
-    p.style.bottom = "0";
-
-    doc.getElementById("container").appendChild(p);
-  });
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  await promisePopupNotification("click-to-play-plugins");
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let plugin = content.document.getElementById("test");
-    let doc = content.document;
-    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-    Assert.ok(!overlay || overlay.getAttribute("sizing") == "blank",
-      "Test 4, overlay should be blank.");
-  });
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_CTP_overlay_styles.js b/browser/base/content/test/plugins/xbl/browser_CTP_overlay_styles.js
deleted file mode 100644
index 66806df12a42..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_CTP_overlay_styles.js
+++ /dev/null
@@ -1,95 +0,0 @@
-/* import-globals-from ../head.js */
-
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-"use strict";
-
-/* This test ensures that the click-to-play "Activate Plugin" overlay
- * is shown in the right style (which is dependent on its size).
- */
-
-const rootDir = getRootDirectory(gTestPath);
-const gTestRoot = rootDir.replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-
-var gTestBrowser = null;
-
-const gTestcases = {
-
-  // 10x10
-  testcase1: {
-    sizing: "blank",
-    notext: null,
-  },
-
-  // 40x40
-  testcase2: {
-    sizing: "tiny",
-    notext: "notext",
-  },
-
-  // 100x70
-  testcase3: {
-    sizing: "reduced",
-    notext: "notext",
-  },
-
-  // 200x200
-  testcase4: {
-    sizing: null,
-    notext: "notext",
-  },
-
-  // 300x300
-  testcase5: {
-    sizing: null,
-    notext: null,
-  },
-};
-
-
-add_task(async function() {
-  registerCleanupFunction(function() {
-    clearAllPluginPermissions();
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    gBrowser.removeCurrentTab();
-    gTestBrowser = null;
-  });
-});
-
-add_task(async function() {
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-  gTestBrowser = gBrowser.selectedBrowser;
-
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Test Plug-in");
-
-  let popupNotification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(!popupNotification, "Sanity check, should not have a click-to-play notification");
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_overlay_styles.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  await ContentTask.spawn(gTestBrowser, gTestcases, async function(testcases) {
-    let doc = content.document;
-
-    for (let testcaseId of Object.keys(testcases)) {
-      let plugin = doc.querySelector(`#${testcaseId} > object`);
-      let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-      Assert.ok(overlay, `overlay exists in ${testcaseId}`);
-
-      let expectations = testcases[testcaseId];
-
-      Assert.ok(overlay.classList.contains("visible"),
-                `The expected visibility is correct in ${testcaseId}`);
-
-      Assert.ok(overlay.getAttribute("sizing") == expectations.sizing,
-                `The expected sizing is correct in ${testcaseId}`);
-
-      Assert.ok(overlay.getAttribute("notext") == expectations.notext,
-                `The expected notext is correct in ${testcaseId}`);
-    }
-  });
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_CTP_resize.js b/browser/base/content/test/plugins/xbl/browser_CTP_resize.js
deleted file mode 100644
index 9f8ed2a38ded..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_CTP_resize.js
+++ /dev/null
@@ -1,132 +0,0 @@
-/* import-globals-from ../head.js */
-
-var rootDir = getRootDirectory(gTestPath);
-const gTestRoot = rootDir.replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gTestBrowser = null;
-
-add_task(async function() {
-  registerCleanupFunction(function() {
-    clearAllPluginPermissions();
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    Services.prefs.clearUserPref("extensions.blocklist.suppressUI");
-    gBrowser.removeCurrentTab();
-    window.focus();
-    gTestBrowser = null;
-  });
-});
-
-add_task(async function() {
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-  Services.prefs.setBoolPref("extensions.blocklist.suppressUI", true);
-
-  let newTab = BrowserTestUtils.addTab(gBrowser);
-  gBrowser.selectedTab = newTab;
-  gTestBrowser = gBrowser.selectedBrowser;
-
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Test Plug-in");
-
-  let popupNotification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(!popupNotification, "Test 1, Should not have a click-to-play notification");
-
-  await promiseTabLoadEvent(newTab, gTestRoot + "plugin_small.html"); // 10x10 plugin
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  await promisePopupNotification("click-to-play-plugins");
-});
-
-// Test that the overlay is hidden for "small" plugin elements and is shown
-// once they are resized to a size that can hold the overlay
-add_task(async function() {
-  let popupNotification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(popupNotification, "Test 2, Should have a click-to-play notification");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-    Assert.ok(!overlay || overlay.getAttribute("sizing") == "blank",
-      "Test 2, overlay should be blank.");
-  });
-});
-
-add_task(async function() {
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let plugin = content.document.getElementById("test");
-    plugin.style.width = "300px";
-  });
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-    Assert.ok(!overlay || overlay.getAttribute("sizing") == "blank",
-      "Test 3, overlay should be blank.");
-  });
-});
-
-
-add_task(async function() {
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let plugin = content.document.getElementById("test");
-    plugin.style.height = "300px";
-  });
-
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    content.document.getElementById("test").clientTop;
-  });
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-    Assert.ok(overlay && overlay.getAttribute("sizing") != "blank",
-      "Test 4, overlay should be visible.");
-  });
-});
-
-add_task(async function() {
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let plugin = content.document.getElementById("test");
-    plugin.style.width = "10px";
-    plugin.style.height = "10px";
-  });
-
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    content.document.getElementById("test").clientTop;
-  });
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-    Assert.ok(!overlay || overlay.getAttribute("sizing") == "blank",
-      "Test 5, overlay should be blank.");
-  });
-});
-
-add_task(async function() {
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let plugin = content.document.getElementById("test");
-    plugin.style.height = "300px";
-    plugin.style.width = "300px";
-  });
-
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    content.document.getElementById("test").clientTop;
-  });
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-    Assert.ok(overlay && overlay.getAttribute("sizing") != "blank",
-      "Test 6, overlay should be visible.");
-  });
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_CTP_shouldShowOverlay.js b/browser/base/content/test/plugins/xbl/browser_CTP_shouldShowOverlay.js
deleted file mode 100644
index 621f8102b521..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_CTP_shouldShowOverlay.js
+++ /dev/null
@@ -1,64 +0,0 @@
-/* import-globals-from ../head.js */
-
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-"use strict";
-
-/* This test ensures that the click-to-play "Activate Plugin" overlay
- * is shown when expected.
- * All testcases are in the plugin_shouldShowOverlay.html file.
- *
- * Note: Technically, the overlay is *always* shown. When this test was
- * originally written, the meaning of "shown" was "shown with the contents",
- * as opposed to "shown as blank". The behavior hasn't changed, but the naming
- * has: now, a "shown as blank" overlay no longer receives a ".hidden" class.
- * It receives a sizing="blank" attribute.
- */
-
-var rootDir = getRootDirectory(gTestPath);
-const gTestRoot = rootDir.replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-
-var gTestBrowser = null;
-
-add_task(async function() {
-  registerCleanupFunction(function() {
-    clearAllPluginPermissions();
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    gBrowser.removeCurrentTab();
-    gTestBrowser = null;
-  });
-});
-
-add_task(async function() {
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-  gTestBrowser = gBrowser.selectedBrowser;
-
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Test Plug-in");
-
-  let popupNotification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(!popupNotification, "Sanity check, should not have a click-to-play notification");
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_shouldShowOverlay.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let testcases = doc.querySelectorAll(".testcase");
-
-    for (let testcase of testcases) {
-      let plugin = testcase.querySelector("object");
-      Assert.ok(plugin, `plugin exists in ${testcase.id}`);
-
-      let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-      Assert.ok(overlay, `overlay exists in ${testcase.id}`);
-
-      let expectedVisibility = (testcase.getAttribute("shouldshow") == "true");
-      Assert.ok((overlay.getAttribute("sizing") != "blank") == expectedVisibility,
-                `The expected visibility is correct in ${testcase.id}`);
-    }
-  });
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_CTP_zoom.js b/browser/base/content/test/plugins/xbl/browser_CTP_zoom.js
deleted file mode 100644
index 3ed1db341382..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_CTP_zoom.js
+++ /dev/null
@@ -1,64 +0,0 @@
-/* import-globals-from ../head.js */
-
-"use strict";
-
-var rootDir = getRootDirectory(gTestPath);
-const gTestRoot = rootDir.replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-
-var gTestBrowser = null;
-
-add_task(async function() {
-  registerCleanupFunction(function() {
-    clearAllPluginPermissions();
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    Services.prefs.clearUserPref("extensions.blocklist.suppressUI");
-    FullZoom.reset(); // must be called before closing the tab we zoomed!
-    gBrowser.removeCurrentTab();
-    window.focus();
-    gTestBrowser = null;
-  });
-});
-
-add_task(async function() {
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-  Services.prefs.setBoolPref("extensions.blocklist.suppressUI", true);
-
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-  gTestBrowser = gBrowser.selectedBrowser;
-
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Test Plug-in");
-
-  let popupNotification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(!popupNotification, "Test 1, Should not have a click-to-play notification");
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_zoom.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  await promisePopupNotification("click-to-play-plugins");
-});
-
-// Enlarges the zoom level 4 times and tests that the overlay is
-// visible after each enlargement.
-add_task(async function() {
-  for (let count = 0; count < 4; count++) {
-
-    FullZoom.enlarge();
-
-    // Reload the page
-    await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_zoom.html");
-    await promiseUpdatePluginBindings(gTestBrowser);
-    await ContentTask.spawn(gTestBrowser, { count }, async function(args) {
-      let doc = content.document;
-      let plugin = doc.getElementById("test");
-      let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-      Assert.ok(overlay && overlay.classList.contains("visible"),
-        "Overlay should be visible for zoom change count " + args.count);
-    });
-  }
-});
-
-
diff --git a/browser/base/content/test/plugins/xbl/browser_blocking.js b/browser/base/content/test/plugins/xbl/browser_blocking.js
deleted file mode 100644
index f3081a31c14f..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_blocking.js
+++ /dev/null
@@ -1,309 +0,0 @@
-/* import-globals-from ../head.js */
-
-var gTestRoot = getRootDirectory(gTestPath).replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gTestBrowser = null;
-var gPluginHost = Cc["@mozilla.org/plugin/host;1"].getService(Ci.nsIPluginHost);
-
-function updateAllTestPlugins(aState) {
-  setTestPluginEnabledState(aState, "Test Plug-in");
-  setTestPluginEnabledState(aState, "Second Test Plug-in");
-}
-
-add_task(async function() {
-  registerCleanupFunction(async function() {
-    clearAllPluginPermissions();
-    updateAllTestPlugins(Ci.nsIPluginTag.STATE_ENABLED);
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    Services.prefs.clearUserPref("extensions.blocklist.suppressUI");
-    await asyncSetAndUpdateBlocklist(gTestRoot + "blockNoPlugins.xml", gTestBrowser);
-    resetBlocklist();
-    gBrowser.removeCurrentTab();
-    window.focus();
-    gTestBrowser = null;
-  });
-});
-
-add_task(async function() {
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-  gTestBrowser = gBrowser.selectedBrowser;
-
-  updateAllTestPlugins(Ci.nsIPluginTag.STATE_CLICKTOPLAY);
-
-  Services.prefs.setBoolPref("extensions.blocklist.suppressUI", true);
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-
-  // Prime the content process
-  await promiseTabLoadEvent(gBrowser.selectedTab, "data:text/html,<html>hi</html>");
-});
-
-// Tests a vulnerable, updatable plugin
-
-add_task(async function() {
-  // enable hard blocklisting of test
-  await asyncSetAndUpdateBlocklist(gTestRoot + "blockPluginVulnerableUpdatable.xml", gTestBrowser);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  await promisePopupNotification("click-to-play-plugins");
-
-  let pluginInfo = await promiseForPluginInfo("test");
-  is(pluginInfo.pluginFallbackType, Ci.nsIObjectLoadingContent.PLUGIN_VULNERABLE_UPDATABLE,
-     "Test 18a, plugin fallback type should be PLUGIN_VULNERABLE_UPDATABLE");
-  ok(!pluginInfo.activated, "Test 18a, Plugin should not be activated");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-    Assert.ok(overlay && overlay.classList.contains("visible"),
-      "Test 18a, Plugin overlay should exist, not be hidden");
-
-    let updateLink = doc.getAnonymousElementByAttribute(plugin, "anonid", "checkForUpdatesLink");
-    Assert.ok(updateLink.style.visibility != "hidden",
-      "Test 18a, Plugin should have an update link");
-  });
-
-  let promise = BrowserTestUtils.waitForEvent(gBrowser.tabContainer, "TabOpen", true);
-
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let updateLink = doc.getAnonymousElementByAttribute(plugin, "anonid", "checkForUpdatesLink");
-    let bounds = updateLink.getBoundingClientRect();
-    let left = (bounds.left + bounds.right) / 2;
-    let top = (bounds.top + bounds.bottom) / 2;
-    let utils = content.windowUtils;
-    utils.sendMouseEvent("mousedown", left, top, 0, 1, 0, false, 0, 0);
-    utils.sendMouseEvent("mouseup", left, top, 0, 1, 0, false, 0, 0);
-  });
-  await promise;
-
-  promise = BrowserTestUtils.waitForEvent(gBrowser.tabContainer, "TabClose", true);
-  gBrowser.removeCurrentTab();
-  await promise;
-});
-
-add_task(async function() {
-  // clicking the update link should not activate the plugin
-  let pluginInfo = await promiseForPluginInfo("test");
-  is(pluginInfo.pluginFallbackType, Ci.nsIObjectLoadingContent.PLUGIN_VULNERABLE_UPDATABLE,
-     "Test 18a, plugin fallback type should be PLUGIN_VULNERABLE_UPDATABLE");
-  ok(!pluginInfo.activated, "Test 18b, Plugin should not be activated");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-    Assert.ok(overlay && overlay.classList.contains("visible"),
-      "Test 18b, Plugin overlay should exist, not be hidden");
-  });
-});
-
-// Tests a vulnerable plugin with no update
-add_task(async function() {
-  updateAllTestPlugins(Ci.nsIPluginTag.STATE_CLICKTOPLAY);
-
-  await asyncSetAndUpdateBlocklist(gTestRoot + "blockPluginVulnerableNoUpdate.xml", gTestBrowser);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let notification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(notification, "Test 18c, Should have a click-to-play notification");
-
-  let pluginInfo = await promiseForPluginInfo("test");
-  is(pluginInfo.pluginFallbackType, Ci.nsIObjectLoadingContent.PLUGIN_VULNERABLE_NO_UPDATE,
-     "Test 18c, plugin fallback type should be PLUGIN_VULNERABLE_NO_UPDATE");
-  ok(!pluginInfo.activated, "Test 18c, Plugin should not be activated");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-    Assert.ok(overlay && overlay.classList.contains("visible"),
-      "Test 18c, Plugin overlay should exist, not be hidden");
-
-    let updateLink = doc.getAnonymousElementByAttribute(plugin, "anonid", "checkForUpdatesLink");
-    Assert.ok(updateLink && updateLink.style.display != "block",
-      "Test 18c, Plugin should not have an update link");
-  });
-
-  // check that click "Allow" works with blocked plugins
-  await promiseForNotificationShown(notification);
-
-  PopupNotifications.panel.firstElementChild.button.click();
-
-  pluginInfo = await promiseForPluginInfo("test");
-  is(pluginInfo.pluginFallbackType, Ci.nsIObjectLoadingContent.PLUGIN_VULNERABLE_NO_UPDATE,
-     "Test 18c, plugin fallback type should be PLUGIN_VULNERABLE_NO_UPDATE");
-  ok(pluginInfo.activated, "Test 18c, Plugin should be activated");
-  let enabledState = getTestPluginEnabledState();
-  ok(enabledState, "Test 18c, Plugin enabled state should be STATE_CLICKTOPLAY");
-});
-
-// continue testing "Always allow", make sure it sticks.
-add_task(async function() {
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let pluginInfo = await promiseForPluginInfo("test");
-  ok(pluginInfo.activated, "Test 18d, Waited too long for plugin to activate");
-
-  clearAllPluginPermissions();
-});
-
-// clicking the in-content overlay of a vulnerable plugin should bring
-// up the notification and not directly activate the plugin
-add_task(async function() {
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let notification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(notification, "Test 18f, Should have a click-to-play notification");
-  ok(notification.dismissed, "Test 18f, notification should start dismissed");
-
-  let pluginInfo = await promiseForPluginInfo("test");
-  ok(!pluginInfo.activated, "Test 18f, Waited too long for plugin to activate");
-
-  var oldEventCallback = notification.options.eventCallback;
-  let promise = promiseForCondition(() => oldEventCallback == null);
-  notification.options.eventCallback = function() {
-    if (oldEventCallback) {
-      oldEventCallback();
-    }
-    oldEventCallback = null;
-  };
-
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let bounds = plugin.getBoundingClientRect();
-    let left = (bounds.left + bounds.right) / 2;
-    let top = (bounds.top + bounds.bottom) / 2;
-    let utils = content.windowUtils;
-    utils.sendMouseEvent("mousedown", left, top, 0, 1, 0, false, 0, 0);
-    utils.sendMouseEvent("mouseup", left, top, 0, 1, 0, false, 0, 0);
-  });
-  await promise;
-
-  ok(notification, "Test 18g, Should have a click-to-play notification");
-  ok(!notification.dismissed, "Test 18g, notification should be open");
-
-  pluginInfo = await promiseForPluginInfo("test");
-  ok(!pluginInfo.activated, "Test 18g, Plugin should not be activated");
-});
-
-// Test that "always allow"-ing a plugin will not allow it when it becomes
-// blocklisted.
-add_task(async function() {
-  await asyncSetAndUpdateBlocklist(gTestRoot + "blockNoPlugins.xml", gTestBrowser);
-
-  updateAllTestPlugins(Ci.nsIPluginTag.STATE_CLICKTOPLAY);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let notification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(notification, "Test 24a, Should have a click-to-play notification");
-
-  // Plugin should start as CTP
-  let pluginInfo = await promiseForPluginInfo("test");
-  is(pluginInfo.pluginFallbackType, Ci.nsIObjectLoadingContent.PLUGIN_CLICK_TO_PLAY,
-     "Test 24a, plugin fallback type should be PLUGIN_CLICK_TO_PLAY");
-  ok(!pluginInfo.activated, "Test 24a, Plugin should not be active.");
-
-  // simulate "allow"
-  await promiseForNotificationShown(notification);
-
-  PopupNotifications.panel.firstElementChild.button.click();
-
-  pluginInfo = await promiseForPluginInfo("test");
-  ok(pluginInfo.activated, "Test 24a, Plugin should be active.");
-
-  await asyncSetAndUpdateBlocklist(gTestRoot + "blockPluginVulnerableUpdatable.xml", gTestBrowser);
-});
-
-// the plugin is now blocklisted, so it should not automatically load
-add_task(async function() {
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let notification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(notification, "Test 24b, Should have a click-to-play notification");
-
-  let pluginInfo = await promiseForPluginInfo("test");
-  is(pluginInfo.pluginFallbackType, Ci.nsIObjectLoadingContent.PLUGIN_VULNERABLE_UPDATABLE,
-     "Test 24b, plugin fallback type should be PLUGIN_VULNERABLE_UPDATABLE");
-  ok(!pluginInfo.activated, "Test 24b, Plugin should not be active.");
-
-  // simulate "allow"
-  await promiseForNotificationShown(notification);
-
-  PopupNotifications.panel.firstElementChild.button.click();
-
-  pluginInfo = await promiseForPluginInfo("test");
-  ok(pluginInfo.activated, "Test 24b, Plugin should be active.");
-
-  clearAllPluginPermissions();
-
-  await asyncSetAndUpdateBlocklist(gTestRoot + "blockNoPlugins.xml", gTestBrowser);
-});
-
-// Plugin sync removal test. Note this test produces a notification drop down since
-// the plugin we add has zero dims.
-add_task(async function() {
-  updateAllTestPlugins(Ci.nsIPluginTag.STATE_CLICKTOPLAY);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_syncRemoved.html");
-
-  // Maybe there some better trick here, we need to wait for the page load, then
-  // wait for the js to execute in the page.
-  await waitForMs(500);
-
-  let notification = PopupNotifications.getNotification("click-to-play-plugins");
-  ok(notification, "Test 25: There should be a plugin notification even if the plugin was immediately removed");
-  ok(notification.dismissed, "Test 25: The notification should be dismissed by default");
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, "data:text/html,<html>hi</html>");
-});
-
-// Tests a page with a blocked plugin in it and make sure the infoURL property
-// the blocklist file gets used.
-add_task(async function() {
-  clearAllPluginPermissions();
-
-  await asyncSetAndUpdateBlocklist(gTestRoot + "blockPluginInfoURL.xml", gTestBrowser);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let notification = PopupNotifications.getNotification("click-to-play-plugins");
-
-  // Since the plugin notification is dismissed by default, reshow it.
-  await promiseForNotificationShown(notification);
-
-  let pluginInfo = await promiseForPluginInfo("test");
-  is(pluginInfo.pluginFallbackType, Ci.nsIObjectLoadingContent.PLUGIN_BLOCKLISTED,
-     "Test 26, plugin fallback type should be PLUGIN_BLOCKLISTED");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let plugin = content.document.getElementById("test");
-    let objLoadingContent = plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    Assert.ok(!objLoadingContent.activated, "Plugin should not be activated.");
-  });
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_blocklist_content.js b/browser/base/content/test/plugins/xbl/browser_blocklist_content.js
deleted file mode 100644
index 8780b4b395d3..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_blocklist_content.js
+++ /dev/null
@@ -1,104 +0,0 @@
-/* import-globals-from ../head.js */
-
-var gTestBrowser = null;
-var gTestRoot = getRootDirectory(gTestPath).replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gChromeRoot = getRootDirectory(gTestPath);
-
-add_task(async function() {
-  registerCleanupFunction(async function() {
-    clearAllPluginPermissions();
-    Services.prefs.clearUserPref("extensions.blocklist.suppressUI");
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    await asyncSetAndUpdateBlocklist(gTestRoot + "blockNoPlugins.xml", gTestBrowser);
-    resetBlocklist();
-    gBrowser.removeCurrentTab();
-    window.focus();
-    gTestBrowser = null;
-  });
-});
-
-add_task(async function() {
-  Services.prefs.setBoolPref("extensions.blocklist.suppressUI", true);
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-  gTestBrowser = gBrowser.selectedBrowser;
-
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-
-  // Prime the blocklist service, the remote service doesn't launch on startup.
-  await promiseTabLoadEvent(gBrowser.selectedTab, "data:text/html,<html></html>");
-});
-
-add_task(async function() {
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  await asyncSetAndUpdateBlocklist(gTestRoot + "blockNoPlugins.xml", gTestBrowser);
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let test = content.document.getElementById("test");
-    Assert.ok(test.activated, "task 1a: test plugin should be activated!");
-  });
-});
-
-// Load a fresh page, load a new plugin blocklist, then load the same page again.
-add_task(async function() {
-  await promiseTabLoadEvent(gBrowser.selectedTab, "data:text/html,<html>GO!</html>");
-  await asyncSetAndUpdateBlocklist(gTestRoot + "blockPluginHard.xml", gTestBrowser);
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let test = content.document.getElementById("test");
-    ok(!test.activated, "task 2a: test plugin shouldn't activate!");
-  });
-});
-
-// Unload the block list and lets do this again, only this time lets
-// hack around in the content blocklist service maliciously.
-add_task(async function() {
-  await promiseTabLoadEvent(gBrowser.selectedTab, "data:text/html,<html>GO!</html>");
-
-  await asyncSetAndUpdateBlocklist(gTestRoot + "blockNoPlugins.xml", gTestBrowser);
-
-  // Hack the planet! Load our blocklist shim, so we can mess with blocklist
-  // return results in the content process. Active until we close our tab.
-  let mm = gTestBrowser.messageManager;
-  info("test 3a: loading " + gChromeRoot + "blocklist_proxy.js\n");
-  mm.loadFrameScript(gChromeRoot + "blocklist_proxy.js", true);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let test = content.document.getElementById("test");
-    Assert.ok(test.activated, "task 3a: test plugin should be activated!");
-  });
-});
-
-// Load a fresh page, load a new plugin blocklist, then load the same page again.
-add_task(async function() {
-  await promiseTabLoadEvent(gBrowser.selectedTab, "data:text/html,<html>GO!</html>");
-  await asyncSetAndUpdateBlocklist(gTestRoot + "blockPluginHard.xml", gTestBrowser);
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let test = content.document.getElementById("test");
-    Assert.ok(!test.activated, "task 4a: test plugin shouldn't activate!");
-  });
-
-  await asyncSetAndUpdateBlocklist(gTestRoot + "blockNoPlugins.xml", gTestBrowser);
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_bug743421.js b/browser/base/content/test/plugins/xbl/browser_bug743421.js
deleted file mode 100644
index b93560a43e65..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_bug743421.js
+++ /dev/null
@@ -1,118 +0,0 @@
-/* import-globals-from ../head.js */
-
-var gTestRoot = getRootDirectory(gTestPath).replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gTestBrowser = null;
-
-add_task(async function() {
-  registerCleanupFunction(async function() {
-    clearAllPluginPermissions();
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    await asyncSetAndUpdateBlocklist(gTestRoot + "blockNoPlugins.xml", gTestBrowser);
-    resetBlocklist();
-    gBrowser.removeCurrentTab();
-    window.focus();
-    gTestBrowser = null;
-  });
-});
-
-add_task(async function() {
-  let newTab = BrowserTestUtils.addTab(gBrowser);
-  gBrowser.selectedTab = newTab;
-  gTestBrowser = gBrowser.selectedBrowser;
-
-  Services.prefs.setBoolPref("extensions.blocklist.suppressUI", true);
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Test Plug-in");
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Second Test Plug-in");
-
-  // Prime the blocklist service, the remote service doesn't launch on startup.
-  await promiseTabLoadEvent(gBrowser.selectedTab, "data:text/html,<html></html>");
-
-  await asyncSetAndUpdateBlocklist(gTestRoot + "blockNoPlugins.xml", gTestBrowser);
-});
-
-// Tests that navigation within the page and the window.history API doesn't break click-to-play state.
-add_task(async function() {
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_add_dynamically.html");
-
-  let notification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(!notification, "Test 1a, Should not have a click-to-play notification");
-
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    new XPCNativeWrapper(XPCNativeWrapper.unwrap(content).addPlugin());
-  });
-
-  await promisePopupNotification("click-to-play-plugins");
-});
-
-add_task(async function() {
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let plugin = content.document.getElementsByTagName("embed")[0];
-    let objLoadingContent = plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    Assert.ok(!objLoadingContent.activated, "Test 1b, Plugin should not be activated");
-  });
-
-  // Click the activate button on doorhanger to make sure it works
-  let notification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-
-  await promiseForNotificationShown(notification);
-
-  PopupNotifications.panel.firstElementChild.button.click();
-
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let plugin = content.document.getElementsByTagName("embed")[0];
-    let objLoadingContent = plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    Assert.ok(objLoadingContent.activated, "Test 1b, Plugin should be activated");
-  });
-});
-
-add_task(async function() {
-  let notification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(notification, "Test 1c, Should still have a click-to-play notification");
-
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    new XPCNativeWrapper(XPCNativeWrapper.unwrap(content).addPlugin());
-    let plugin = content.document.getElementsByTagName("embed")[1];
-    let objLoadingContent = plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    Assert.ok(objLoadingContent.activated,
-      "Test 1c, Newly inserted plugin in activated page should be activated");
-  });
-});
-
-add_task(async function() {
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let plugin = content.document.getElementsByTagName("embed")[1];
-    let objLoadingContent = plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    Assert.ok(objLoadingContent.activated, "Test 1d, Plugin should be activated");
-
-    let promise = ContentTaskUtils.waitForEvent(content, "hashchange");
-    content.location += "#anchorNavigation";
-    await promise;
-  });
-});
-
-add_task(async function() {
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    new XPCNativeWrapper(XPCNativeWrapper.unwrap(content).addPlugin());
-    let plugin = content.document.getElementsByTagName("embed")[2];
-    let objLoadingContent = plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    Assert.ok(objLoadingContent.activated, "Test 1e, Plugin should be activated");
-  });
-});
-
-add_task(async function() {
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let plugin = content.document.getElementsByTagName("embed")[2];
-    let objLoadingContent = plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    Assert.ok(objLoadingContent.activated, "Test 1f, Plugin should be activated");
-
-    content.history.replaceState({}, "", "replacedState");
-    new XPCNativeWrapper(XPCNativeWrapper.unwrap(content).addPlugin());
-    plugin = content.document.getElementsByTagName("embed")[3];
-    objLoadingContent = plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    Assert.ok(objLoadingContent.activated, "Test 1g, Plugin should be activated");
-  });
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_bug744745.js b/browser/base/content/test/plugins/xbl/browser_bug744745.js
deleted file mode 100644
index 2a7b1bfa0b59..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_bug744745.js
+++ /dev/null
@@ -1,52 +0,0 @@
-/* import-globals-from ../head.js */
-
-var gTestRoot = getRootDirectory(gTestPath).replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gTestBrowser = null;
-var gNumPluginBindingsAttached = 0;
-
-function pluginBindingAttached() {
-  gNumPluginBindingsAttached++;
-  if (gNumPluginBindingsAttached != 1) {
-    ok(false, "if we've gotten here, something is quite wrong");
-  }
-}
-
-add_task(async function() {
-  registerCleanupFunction(function() {
-    gTestBrowser.removeEventListener("PluginBindingAttached", pluginBindingAttached, true, true);
-    clearAllPluginPermissions();
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    gBrowser.removeCurrentTab();
-    window.focus();
-    gTestBrowser = null;
-  });
-});
-
-add_task(async function() {
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-  gTestBrowser = gBrowser.selectedBrowser;
-
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Test Plug-in");
-
-  BrowserTestUtils.addContentEventListener(gTestBrowser, "PluginBindingAttached", pluginBindingAttached, true, null, true);
-
-  let testRoot = getRootDirectory(gTestPath).replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-  await promiseTabLoadEvent(gBrowser.selectedTab, testRoot + "plugin_bug744745.html");
-
-  await promiseForCondition(function() { return gNumPluginBindingsAttached == 1; });
-
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let plugin = content.document.getElementById("test");
-    if (!plugin) {
-      Assert.ok(false, "plugin element not available.");
-      return;
-    }
-    // We can't use MochiKit's routine
-    let style = content.getComputedStyle(plugin);
-    Assert.ok(("opacity" in style) && style.opacity == 1, "plugin style properly configured.");
-  });
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_bug787619.js b/browser/base/content/test/plugins/xbl/browser_bug787619.js
deleted file mode 100644
index 257076d59b6f..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_bug787619.js
+++ /dev/null
@@ -1,66 +0,0 @@
-/* import-globals-from ../head.js */
-
-var gTestRoot = getRootDirectory(gTestPath).replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gTestBrowser = null;
-var gWrapperClickCount = 0;
-
-add_task(async function() {
-  registerCleanupFunction(function() {
-    clearAllPluginPermissions();
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    gBrowser.removeCurrentTab();
-    window.focus();
-    gTestBrowser = null;
-  });
-});
-
-add_task(async function() {
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-  gTestBrowser = gBrowser.selectedBrowser;
-
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Test Plug-in");
-
-  let testRoot = getRootDirectory(gTestPath).replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-  await promiseTabLoadEvent(gBrowser.selectedTab, testRoot + "plugin_bug787619.html");
-
-  // Due to layout being async, "PluginBindAttached" may trigger later.
-  // This forces a layout flush, thus triggering it, and schedules the
-  // test so it is definitely executed afterwards.
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  // check plugin state
-  let pluginInfo = await promiseForPluginInfo("plugin");
-  ok(!pluginInfo.activated, "1a plugin should not be activated");
-
-  // click the overlay to prompt
-  let promise = promisePopupNotification("click-to-play-plugins");
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    let plugin = content.document.getElementById("plugin");
-    let bounds = plugin.getBoundingClientRect();
-    let left = (bounds.left + bounds.right) / 2;
-    let top = (bounds.top + bounds.bottom) / 2;
-    let utils = content.windowUtils;
-    utils.sendMouseEvent("mousedown", left, top, 0, 1, 0, false, 0, 0);
-    utils.sendMouseEvent("mouseup", left, top, 0, 1, 0, false, 0, 0);
-  });
-  await promise;
-
-  // check plugin state
-  pluginInfo = await promiseForPluginInfo("plugin");
-  ok(!pluginInfo.activated, "1b plugin should not be activated");
-
-  let condition = () => !PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed &&
-    PopupNotifications.panel.firstElementChild;
-  await promiseForCondition(condition);
-  PopupNotifications.panel.firstElementChild.button.click();
-
-  // check plugin state
-  pluginInfo = await promiseForPluginInfo("plugin");
-  ok(pluginInfo.activated, "plugin should be activated");
-
-  is(gWrapperClickCount, 0, "wrapper should not have received any clicks");
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_bug797677.js b/browser/base/content/test/plugins/xbl/browser_bug797677.js
deleted file mode 100644
index 568e92f088a3..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_bug797677.js
+++ /dev/null
@@ -1,40 +0,0 @@
-/* import-globals-from ../head.js */
-
-var gTestRoot = getRootDirectory(gTestPath).replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gTestBrowser = null;
-var gConsoleErrors = 0;
-
-add_task(async function() {
-  registerCleanupFunction(function() {
-    clearAllPluginPermissions();
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    Services.console.unregisterListener(errorListener);
-    gBrowser.removeCurrentTab();
-    window.focus();
-    gTestBrowser = null;
-  });
-
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-  gTestBrowser = gBrowser.selectedBrowser;
-
-  let errorListener = {
-    observe(aMessage) {
-      if (aMessage.message.includes("NS_ERROR_FAILURE"))
-        gConsoleErrors++;
-    },
-  };
-  Services.console.registerListener(errorListener);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_bug797677.html");
-
-  let pluginInfo = await promiseForPluginInfo("plugin");
-  is(pluginInfo.pluginFallbackType, Ci.nsIObjectLoadingContent.PLUGIN_UNSUPPORTED, "plugin should not have been found.");
-
-  // simple cpows
-  await ContentTask.spawn(gTestBrowser, null, function() {
-    let plugin = content.document.getElementById("plugin");
-    ok(plugin, "plugin should be in the page");
-  });
-  is(gConsoleErrors, 0, "should have no console errors");
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_bug812562.js b/browser/base/content/test/plugins/xbl/browser_bug812562.js
deleted file mode 100644
index 3bb135607014..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_bug812562.js
+++ /dev/null
@@ -1,80 +0,0 @@
-/* import-globals-from ../head.js */
-
-var gTestRoot = getRootDirectory(gTestPath).replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gTestBrowser = null;
-
-add_task(async function() {
-  registerCleanupFunction(async function() {
-    clearAllPluginPermissions();
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    await asyncSetAndUpdateBlocklist(gTestRoot + "blockNoPlugins.xml", gTestBrowser);
-    resetBlocklist();
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    gBrowser.removeCurrentTab();
-    window.focus();
-    gTestBrowser = null;
-  });
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-  gTestBrowser = gBrowser.selectedBrowser;
-
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Test Plug-in");
-
-  // Prime the blocklist service, the remote service doesn't launch on startup.
-  await promiseTabLoadEvent(gBrowser.selectedTab, "data:text/html,<html></html>");
-});
-
-// Tests that the going back will reshow the notification for click-to-play
-// blocklisted plugins
-add_task(async function() {
-  await asyncSetAndUpdateBlocklist(gTestRoot + "blockPluginVulnerableUpdatable.xml", gTestBrowser);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let popupNotification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(popupNotification, "test part 1: Should have a click-to-play notification");
-
-  let pluginInfo = await promiseForPluginInfo("test");
-  is(pluginInfo.pluginFallbackType, Ci.nsIObjectLoadingContent.PLUGIN_VULNERABLE_UPDATABLE, "plugin should be marked as VULNERABLE");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    Assert.ok(!!content.document.getElementById("test"),
-      "test part 1: plugin should not be activated");
-  });
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, "data:text/html,<html></html>");
-});
-
-add_task(async function() {
-  let popupNotification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(!popupNotification, "test part 2: Should not have a click-to-play notification");
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    Assert.ok(!content.document.getElementById("test"),
-      "test part 2: plugin should not be activated");
-  });
-
-  let obsPromise = TestUtils.topicObserved("PopupNotifications-updateNotShowing");
-  let overlayPromise = promisePopupNotification("click-to-play-plugins");
-  gTestBrowser.goBack();
-  await obsPromise;
-  await overlayPromise;
-});
-
-add_task(async function() {
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let popupNotification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(popupNotification, "test part 3: Should have a click-to-play notification");
-
-  let pluginInfo = await promiseForPluginInfo("test");
-  is(pluginInfo.pluginFallbackType, Ci.nsIObjectLoadingContent.PLUGIN_VULNERABLE_UPDATABLE, "plugin should be marked as VULNERABLE");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    Assert.ok(!!content.document.getElementById("test"),
-      "test part 3: plugin should not be activated");
-  });
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_bug818118.js b/browser/base/content/test/plugins/xbl/browser_bug818118.js
deleted file mode 100644
index 006c04e0b710..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_bug818118.js
+++ /dev/null
@@ -1,42 +0,0 @@
-/* import-globals-from ../head.js */
-
-var gTestRoot = getRootDirectory(gTestPath).replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gTestBrowser = null;
-
-add_task(async function() {
-  registerCleanupFunction(function() {
-    clearAllPluginPermissions();
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    gBrowser.removeCurrentTab();
-    window.focus();
-    gTestBrowser = null;
-  });
-});
-
-add_task(async function() {
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-  gTestBrowser = gBrowser.selectedBrowser;
-
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Test Plug-in");
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_both.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let popupNotification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(popupNotification, "should have a click-to-play notification");
-
-  let pluginInfo = await promiseForPluginInfo("test");
-  is(pluginInfo.pluginFallbackType, Ci.nsIObjectLoadingContent.PLUGIN_CLICK_TO_PLAY, "plugin should be click to play");
-  ok(!pluginInfo.activated, "plugin should not be activated");
-
-  await ContentTask.spawn(gTestBrowser, null, () => {
-    let unknown = content.document.getElementById("unknown");
-    ok(unknown, "should have unknown plugin in page");
-  });
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_bug820497.js b/browser/base/content/test/plugins/xbl/browser_bug820497.js
deleted file mode 100644
index 6d65e96f9c96..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_bug820497.js
+++ /dev/null
@@ -1,73 +0,0 @@
-/* import-globals-from ../head.js */
-
-var gTestRoot = getRootDirectory(gTestPath).replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gTestBrowser = null;
-var gNumPluginBindingsAttached = 0;
-
-add_task(async function() {
-  registerCleanupFunction(function() {
-    clearAllPluginPermissions();
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    gBrowser.removeCurrentTab();
-    window.focus();
-    gTestBrowser = null;
-  });
-});
-
-add_task(async function() {
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-  gTestBrowser = gBrowser.selectedBrowser;
-
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Test Plug-in");
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Second Test Plug-in");
-
-  BrowserTestUtils.addContentEventListener(gTestBrowser, "PluginBindingAttached", function() { gNumPluginBindingsAttached++; }, true, null, true);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_bug820497.html");
-
-  await promiseForCondition(function() { return gNumPluginBindingsAttached == 1; });
-
-  await ContentTask.spawn(gTestBrowser, null, () => {
-    // Note we add the second plugin in the code farther down, so there's
-    // no way we got here with anything but one plugin loaded.
-    let doc = content.document;
-    let testplugin = doc.getElementById("test");
-    ok(testplugin, "should have test plugin");
-    let secondtestplugin = doc.getElementById("secondtest");
-    ok(!secondtestplugin, "should not yet have second test plugin");
-  });
-
-  await promisePopupNotification("click-to-play-plugins");
-  let notification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(notification, "should have a click-to-play notification");
-
-  await promiseForNotificationShown(notification);
-
-  is(notification.options.pluginData.size, 1, "should be 1 type of plugin in the popup notification");
-
-  await ContentTask.spawn(gTestBrowser, {}, async function() {
-    XPCNativeWrapper.unwrap(content).addSecondPlugin();
-  });
-
-  await promiseForCondition(function() { return gNumPluginBindingsAttached == 2; });
-
-  await ContentTask.spawn(gTestBrowser, null, () => {
-    let doc = content.document;
-    let testplugin = doc.getElementById("test");
-    ok(testplugin, "should have test plugin");
-    let secondtestplugin = doc.getElementById("secondtest");
-    ok(secondtestplugin, "should have second test plugin");
-  });
-
-  notification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-
-  ok(notification, "should have popup notification");
-
-  await promiseForNotificationShown(notification);
-
-  is(notification.options.pluginData.size, 2, "aited too long for 2 types of plugins in popup notification");
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_clearplugindata.html b/browser/base/content/test/plugins/xbl/browser_clearplugindata.html
deleted file mode 100644
index d32af308c264..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_clearplugindata.html
+++ /dev/null
@@ -1,29 +0,0 @@
-<!--
-  Any copyright is dedicated to the Public Domain.
-  http://creativecommons.org/publicdomain/zero/1.0/
--->
-<html>
-  <head>
-    <title>Plugin Clear Site Data sanitize test</title>
-
-    <embed id="plugin1" type="application/x-test" width="200" height="200"></embed>
-
-    <script type="application/javascript">
-      function testSteps() {
-        // Make sure clearing by timerange is supported.
-        var p = document.getElementById("plugin1");
-        p.setSitesWithDataCapabilities(true);
-
-        p.setSitesWithData(
-          "foo.com:0:5," +
-          "bar.com:0:100," +
-          "baz.com:1:5," +
-          "qux.com:1:100"
-        );
-      }
-    </script>
-  </head>
-
-  <body onload="testSteps();"></body>
-
-</html>
diff --git a/browser/base/content/test/plugins/xbl/browser_clearplugindata.js b/browser/base/content/test/plugins/xbl/browser_clearplugindata.js
deleted file mode 100644
index aa7358826722..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_clearplugindata.js
+++ /dev/null
@@ -1,113 +0,0 @@
-/* import-globals-from ../head.js */
-
-var gTestRoot = getRootDirectory(gTestPath).replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gPluginHost = Cc["@mozilla.org/plugin/host;1"].getService(Ci.nsIPluginHost);
-var gTestBrowser = null;
-
-// Test clearing plugin data using Sanitizer.jsm.
-const testURL1 = gTestRoot + "browser_clearplugindata.html";
-const testURL2 = gTestRoot + "browser_clearplugindata_noage.html";
-
-const {Sanitizer} = ChromeUtils.import("resource:///modules/Sanitizer.jsm", {});
-
-const pluginHostIface = Ci.nsIPluginHost;
-var pluginHost = Cc["@mozilla.org/plugin/host;1"].getService(Ci.nsIPluginHost);
-pluginHost.QueryInterface(pluginHostIface);
-
-var pluginTag = getTestPlugin();
-
-function stored(needles) {
-  let something = pluginHost.siteHasData(this.pluginTag, null);
-  if (!needles)
-    return something;
-
-  if (!something)
-    return false;
-
-  for (let i = 0; i < needles.length; ++i) {
-    if (!pluginHost.siteHasData(this.pluginTag, needles[i]))
-      return false;
-  }
-  return true;
-}
-
-add_task(async function() {
-  registerCleanupFunction(function() {
-    clearAllPluginPermissions();
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    Services.prefs.clearUserPref("extensions.blocklist.suppressUI");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    if (gTestBrowser) {
-      gBrowser.removeCurrentTab();
-    }
-    window.focus();
-    gTestBrowser = null;
-  });
-
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-});
-
-function setPrefs(cookies, pluginData) {
-  let itemPrefs = Services.prefs.getBranch("privacy.cpd.");
-  itemPrefs.setBoolPref("history", false);
-  itemPrefs.setBoolPref("downloads", false);
-  itemPrefs.setBoolPref("cache", false);
-  itemPrefs.setBoolPref("cookies", cookies);
-  itemPrefs.setBoolPref("formdata", false);
-  itemPrefs.setBoolPref("offlineApps", false);
-  itemPrefs.setBoolPref("passwords", false);
-  itemPrefs.setBoolPref("sessions", false);
-  itemPrefs.setBoolPref("siteSettings", false);
-  itemPrefs.setBoolPref("pluginData", pluginData);
-}
-
-async function testClearingData(url) {
-  // Load page to set data for the plugin.
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-  gTestBrowser = gBrowser.selectedBrowser;
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, url);
-
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  ok(stored(["foo.com", "bar.com", "baz.com", "qux.com"]),
-    "Data stored for sites");
-
-  // Clear 20 seconds ago.
-  // In the case of testURL2 the plugin will throw
-  // NS_ERROR_PLUGIN_TIME_RANGE_NOT_SUPPORTED, which should result in us
-  // clearing all data regardless of age.
-  let now_uSec = Date.now() * 1000;
-  let range = [now_uSec - 20 * 1000000, now_uSec];
-  await Sanitizer.sanitize(null, {range, ignoreTimespan: false});
-
-  if (url == testURL1) {
-    ok(stored(["bar.com", "qux.com"]), "Data stored for sites");
-    ok(!stored(["foo.com"]), "Data cleared for foo.com");
-    ok(!stored(["baz.com"]), "Data cleared for baz.com");
-
-    // Clear everything.
-    await Sanitizer.sanitize(null, {ignoreTimespan: false});
-  }
-
-  ok(!stored(null), "All data cleared");
-
-  gBrowser.removeCurrentTab();
-  gTestBrowser = null;
-}
-
-add_task(async function() {
-  // Test when sanitizing cookies.
-  await setPrefs(true, false);
-  await testClearingData(testURL1);
-  await testClearingData(testURL2);
-
-  // Test when sanitizing pluginData.
-  await setPrefs(false, true);
-  await testClearingData(testURL1);
-  await testClearingData(testURL2);
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_clearplugindata_noage.html b/browser/base/content/test/plugins/xbl/browser_clearplugindata_noage.html
deleted file mode 100644
index 459f666277b6..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_clearplugindata_noage.html
+++ /dev/null
@@ -1,29 +0,0 @@
-<!--
-  Any copyright is dedicated to the Public Domain.
-  http://creativecommons.org/publicdomain/zero/1.0/
--->
-<html>
-  <head>
-    <title>Plugin Clear Site Data sanitize test without age</title>
-
-    <embed id="plugin1" type="application/x-test" width="200" height="200"></embed>
-
-    <script type="application/javascript">
-      function testSteps() {
-        // Make sure clearing by timerange is disabled.
-        var p = document.getElementById("plugin1");
-        p.setSitesWithDataCapabilities(false);
-
-        p.setSitesWithData(
-          "foo.com:0:5," +
-          "bar.com:0:100," +
-          "baz.com:1:5," +
-          "qux.com:1:100"
-        );
-      }
-    </script>
-  </head>
-
-  <body onload="testSteps();"></body>
-
-</html>
diff --git a/browser/base/content/test/plugins/xbl/browser_enable_DRM_prompt.js b/browser/base/content/test/plugins/xbl/browser_enable_DRM_prompt.js
deleted file mode 100644
index 901352eba797..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_enable_DRM_prompt.js
+++ /dev/null
@@ -1,67 +0,0 @@
-/*
- * Bug 1366167 - Tests that the "Enable DRM" prompt shows if EME is requested while EME is disabled.
- */
-
-const TEST_URL =
-  getRootDirectory(gTestPath).replace("chrome://mochitests/content",
-  "https://example.com") + "empty_file.html";
-
-add_task(async function() {
-  await BrowserTestUtils.withNewTab(TEST_URL, async function(browser) {
-    // Note: SpecialPowers.pushPrefEnv has problems with the "Enable DRM"
-    // button on the notification box toggling the prefs. So manually
-    // set/unset the prefs the UI we're testing toggles.
-    let emeWasEnabled = Services.prefs.getBoolPref("media.eme.enabled", false);
-    let cdmWasEnabled = Services.prefs.getBoolPref("media.gmp-widevinecdm.enabled", false);
-
-    // Restore the preferences to their pre-test state on test finish.
-    registerCleanupFunction(function() {
-        Services.prefs.setBoolPref("media.eme.enabled", emeWasEnabled);
-        Services.prefs.setBoolPref("media.gmp-widevinecdm.enabled", cdmWasEnabled);
-    });
-
-    // Turn off EME and Widevine CDM.
-    Services.prefs.setBoolPref("media.eme.enabled", false);
-    Services.prefs.setBoolPref("media.gmp-widevinecdm.enabled", false);
-
-    // Have content request access to Widevine, UI should drop down to
-    // prompt user to enable DRM.
-    let result = await ContentTask.spawn(browser, {}, async function() {
-      try {
-        let config = [{
-          initDataTypes: ["webm"],
-          videoCapabilities: [{contentType: 'video/webm; codecs="vp9"'}],
-        }];
-        await content.navigator.requestMediaKeySystemAccess("com.widevine.alpha", config);
-      } catch (ex) {
-        return {rejected: true};
-      }
-      return {rejected: false};
-    });
-    is(result.rejected, true, "EME request should be denied because EME disabled.");
-
-    // Verify the UI prompt showed.
-    let box = gBrowser.getNotificationBox(browser);
-    let notification = box.currentNotification;
-
-    ok(notification, "Notification should be visible");
-    is(notification.getAttribute("value"), "drmContentDisabled",
-       "Should be showing the right notification");
-
-    // Verify the "Enable DRM" button is there.
-    let buttons = notification.querySelectorAll(".notification-button");
-    is(buttons.length, 1, "Should have one button.");
-
-    // Prepare a Promise that should resolve when the "Enable DRM" button's
-    // page reload completes.
-    let refreshPromise = BrowserTestUtils.browserLoaded(browser);
-    buttons[0].click();
-
-    // Wait for the reload to complete.
-    await refreshPromise;
-
-    // Verify clicking the "Enable DRM" button enabled DRM.
-    let enabled = Services.prefs.getBoolPref("media.eme.enabled", true);
-    is(enabled, true, "EME should be enabled after click on 'Enable DRM' button");
-  });
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_globalplugin_crashinfobar.js b/browser/base/content/test/plugins/xbl/browser_globalplugin_crashinfobar.js
deleted file mode 100644
index f68bf7f28b49..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_globalplugin_crashinfobar.js
+++ /dev/null
@@ -1,36 +0,0 @@
-/* import-globals-from ../head.js */
-
-/**
- * Test that the notification bar for crashed GMPs works.
- */
-add_task(async function() {
-  await BrowserTestUtils.withNewTab({
-    gBrowser,
-    url: "about:blank",
-  }, async function(browser) {
-    await ContentTask.spawn(browser, null, async function() {
-      const GMP_CRASH_EVENT = {
-        pluginID: 1,
-        pluginName: "GlobalTestPlugin",
-        submittedCrashReport: false,
-        bubbles: true,
-        cancelable: true,
-        gmpPlugin: true,
-      };
-
-      let crashEvent = new content.PluginCrashedEvent("PluginCrashed",
-                                                      GMP_CRASH_EVENT);
-      content.dispatchEvent(crashEvent);
-    });
-
-    let notification = await waitForNotificationBar("plugin-crashed", browser);
-
-    let notificationBox = gBrowser.getNotificationBox(browser);
-    ok(notification, "Infobar was shown.");
-    is(notification.priority, notificationBox.PRIORITY_WARNING_MEDIUM,
-       "Correct priority.");
-    is(notification.messageText.textContent,
-       "The GlobalTestPlugin plugin has crashed.",
-       "Correct message.");
-  });
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_iterate_hidden_plugins.js b/browser/base/content/test/plugins/xbl/browser_iterate_hidden_plugins.js
deleted file mode 100644
index 23cc7faf457f..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_iterate_hidden_plugins.js
+++ /dev/null
@@ -1,70 +0,0 @@
-/* import-globals-from ../head.js */
-
-"use strict";
-
-const TEST_PLUGIN_NAME = "Test Plug-in";
-const HIDDEN_CTP_PLUGIN_PREF = "plugins.navigator.hidden_ctp_plugin";
-
-/**
- * If a plugin is click-to-play and named in HIDDEN_CTP_PLUGIN_PREF,
- * then the plugin should be hidden in the navigator.plugins list by default
- * when iterating.
- */
-
-add_task(async function setup() {
-  // We'll make the Test Plugin click-to-play.
-  let originalPluginState = getTestPluginEnabledState();
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY);
-  registerCleanupFunction(() => {
-    setTestPluginEnabledState(originalPluginState);
-  });
-
-  // And then make the plugin hidden.
-  await SpecialPowers.pushPrefEnv({
-    set: [
-      [HIDDEN_CTP_PLUGIN_PREF, TEST_PLUGIN_NAME],
-      ["plugins.show_infobar", true],
-    ],
-  });
-});
-
-/**
- * Tests that if a plugin is click-to-play and in the
- * HIDDEN_CTP_PLUGIN_PREF list, then it shouldn't be visible
- * when iterating navigator.plugins.
- */
-add_task(async function test_plugin_is_hidden_on_iteration() {
-  // The plugin should not be visible when we iterate
-  // navigator.plugins.
-  await BrowserTestUtils.withNewTab({
-    gBrowser,
-    url: "http://example.com",
-  }, async function(browser) {
-    await ContentTask.spawn(browser, TEST_PLUGIN_NAME, async function(pluginName) {
-      let plugins = Array.from(content.navigator.plugins);
-      Assert.ok(plugins.every(p => p.name != pluginName),
-                "Should not find Test Plugin");
-    });
-  });
-
-  // Now clear the HIDDEN_CTP_PLUGIN_PREF temporarily and
-  // make sure we can see the plugin again.
-  await SpecialPowers.pushPrefEnv({
-    set: [[HIDDEN_CTP_PLUGIN_PREF, ""]],
-  });
-
-  // Note that I have to do this in a new tab since navigator
-  // caches navigator.plugins after an initial read.
-  await BrowserTestUtils.withNewTab({
-    gBrowser,
-    url: "http://example.com",
-  }, async function(browser) {
-    await ContentTask.spawn(browser, TEST_PLUGIN_NAME, async function(pluginName) {
-      let plugins = Array.from(content.navigator.plugins);
-      Assert.ok(plugins.some(p => p.name == pluginName),
-                "Should have found the Test Plugin");
-    });
-  });
-
-  await SpecialPowers.popPrefEnv();
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_pluginCrashCommentAndURL.js b/browser/base/content/test/plugins/xbl/browser_pluginCrashCommentAndURL.js
deleted file mode 100644
index f62879236578..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_pluginCrashCommentAndURL.js
+++ /dev/null
@@ -1,249 +0,0 @@
-/* import-globals-from ../head.js */
-
-/* global gBrowser */
-ChromeUtils.import("resource://gre/modules/CrashSubmit.jsm", this);
-
-const SERVER_URL = "http://example.com/browser/toolkit/crashreporter/test/browser/crashreport.sjs";
-
-var gTestRoot = getRootDirectory(gTestPath).replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gTestBrowser = null;
-var config = {};
-
-add_task(async function() {
-  // The test harness sets MOZ_CRASHREPORTER_NO_REPORT, which disables plugin
-  // crash reports.  This test needs them enabled.  The test also needs a mock
-  // report server, and fortunately one is already set up by toolkit/
-  // crashreporter/test/Makefile.in.  Assign its URL to MOZ_CRASHREPORTER_URL,
-  // which CrashSubmit.jsm uses as a server override.
-  let env = Cc["@mozilla.org/process/environment;1"]
-              .getService(Ci.nsIEnvironment);
-  let noReport = env.get("MOZ_CRASHREPORTER_NO_REPORT");
-  let serverUrl = env.get("MOZ_CRASHREPORTER_URL");
-  env.set("MOZ_CRASHREPORTER_NO_REPORT", "");
-  env.set("MOZ_CRASHREPORTER_URL", SERVER_URL);
-
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-  gTestBrowser = gBrowser.selectedBrowser;
-
-  // Crash immediately
-  Services.prefs.setIntPref("dom.ipc.plugins.timeoutSecs", 0);
-
-  registerCleanupFunction(async function() {
-    Services.prefs.clearUserPref("dom.ipc.plugins.timeoutSecs");
-    env.set("MOZ_CRASHREPORTER_NO_REPORT", noReport);
-    env.set("MOZ_CRASHREPORTER_URL", serverUrl);
-    env = null;
-    config = null;
-    gTestBrowser = null;
-    gBrowser.removeCurrentTab();
-    window.focus();
-  });
-});
-
-add_task(async function() {
-  config = {
-    shouldSubmissionUIBeVisible: true,
-    comment: "",
-    urlOptIn: false,
-  };
-
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED);
-
-  let pluginCrashed = promisePluginCrashed();
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_crashCommentAndURL.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  // Wait for the plugin to crash
-  await pluginCrashed;
-
-  let crashReportStatus = TestUtils.topicObserved("crash-report-status", onSubmitStatus);
-
-  // Test that the crash submission UI is actually visible and submit the crash report.
-  await ContentTask.spawn(gTestBrowser, config, async function(aConfig) {
-    let doc = content.document;
-    let plugin = doc.getElementById("plugin");
-    let pleaseSubmit = doc.getAnonymousElementByAttribute(plugin, "anonid", "pleaseSubmit");
-    let submitButton = doc.getAnonymousElementByAttribute(plugin, "anonid", "submitButton");
-    // Test that we don't send the URL when urlOptIn is false.
-    doc.getAnonymousElementByAttribute(plugin, "anonid", "submitURLOptIn").checked = aConfig.urlOptIn;
-    submitButton.click();
-    Assert.equal(content.getComputedStyle(pleaseSubmit).display == "block",
-      aConfig.shouldSubmissionUIBeVisible, "The crash UI should be visible");
-  });
-
-  await crashReportStatus;
-});
-
-add_task(async function() {
-  config = {
-    shouldSubmissionUIBeVisible: true,
-    comment: "a test comment",
-    urlOptIn: true,
-  };
-
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED);
-
-  let pluginCrashed = promisePluginCrashed();
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_crashCommentAndURL.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  // Wait for the plugin to crash
-  await pluginCrashed;
-
-  let crashReportStatus = TestUtils.topicObserved("crash-report-status", onSubmitStatus);
-
-  // Test that the crash submission UI is actually visible and submit the crash report.
-  await ContentTask.spawn(gTestBrowser, config, async function(aConfig) {
-    let doc = content.document;
-    let plugin = doc.getElementById("plugin");
-    let pleaseSubmit = doc.getAnonymousElementByAttribute(plugin, "anonid", "pleaseSubmit");
-    let submitButton = doc.getAnonymousElementByAttribute(plugin, "anonid", "submitButton");
-    // Test that we send the URL when urlOptIn is true.
-    doc.getAnonymousElementByAttribute(plugin, "anonid", "submitURLOptIn").checked = aConfig.urlOptIn;
-    doc.getAnonymousElementByAttribute(plugin, "anonid", "submitComment").value = aConfig.comment;
-    submitButton.click();
-    Assert.equal(content.getComputedStyle(pleaseSubmit).display == "block",
-      aConfig.shouldSubmissionUIBeVisible, "The crash UI should be visible");
-  });
-
-  await crashReportStatus;
-});
-
-add_task(async function() {
-  config = {
-    shouldSubmissionUIBeVisible: false,
-    comment: "",
-    urlOptIn: true,
-  };
-
-  // Deferred promise object used by the test to wait for the crash handler
-  let crashDeferred = PromiseUtils.defer();
-
-  // Clear out any minidumps we create from plugin crashes, this is needed
-  // because we do not submit the crash otherwise the submission process would
-  // have deleted the crash dump files for us.
-  let crashObserver = (subject, topic, data) => {
-    if (topic != "plugin-crashed") {
-      return;
-    }
-
-    let propBag = subject.QueryInterface(Ci.nsIPropertyBag2);
-    let minidumpID = propBag.getPropertyAsAString("pluginDumpID");
-
-    Services.crashmanager.ensureCrashIsPresent(minidumpID).then(() => {
-      let minidumpDir = Services.dirsvc.get("UAppData", Ci.nsIFile);
-      minidumpDir.append("Crash Reports");
-      minidumpDir.append("pending");
-
-      let pluginDumpFile = minidumpDir.clone();
-      pluginDumpFile.append(minidumpID + ".dmp");
-
-      let extraFile = minidumpDir.clone();
-      extraFile.append(minidumpID + ".extra");
-
-      pluginDumpFile.remove(false);
-      extraFile.remove(false);
-      crashDeferred.resolve();
-    });
-  };
-
-  Services.obs.addObserver(crashObserver, "plugin-crashed");
-
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED);
-
-  let pluginCrashed = promisePluginCrashed();
-
-  // Make sure that the plugin container is too small to display the crash submission UI
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_crashCommentAndURL.html?" +
-                            encodeURIComponent(JSON.stringify({width: 300, height: 300})));
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  // Wait for the plugin to crash
-  await pluginCrashed;
-
-  // Test that the crash submission UI is not visible and do not submit a crash report.
-  await ContentTask.spawn(gTestBrowser, config, async function(aConfig) {
-    let doc = content.document;
-    let plugin = doc.getElementById("plugin");
-    let pleaseSubmit = doc.getAnonymousElementByAttribute(plugin, "anonid", "pleaseSubmit");
-    Assert.equal(!!pleaseSubmit && content.getComputedStyle(pleaseSubmit).display == "block",
-      aConfig.shouldSubmissionUIBeVisible, "Plugin crash UI should not be visible");
-  });
-
-  await crashDeferred.promise;
-  Services.obs.removeObserver(crashObserver, "plugin-crashed");
-});
-
-function promisePluginCrashed() {
-  return new ContentTask.spawn(gTestBrowser, {}, async function() {
-    await new Promise((resolve) => {
-      addEventListener("PluginCrashReporterDisplayed", function onPluginCrashed() {
-        removeEventListener("PluginCrashReporterDisplayed", onPluginCrashed);
-        resolve();
-      });
-    });
-  });
-}
-
-function onSubmitStatus(aSubject, aData) {
-  if (aData === "submitting") {
-    return false;
-  }
-
-  is(aData, "success", "The crash report should be submitted successfully");
-
-  let propBag = aSubject.QueryInterface(Ci.nsIPropertyBag);
-  if (aData == "success") {
-    let remoteID = getPropertyBagValue(propBag, "serverCrashID");
-    ok(!!remoteID, "serverCrashID should be set");
-
-    // Remove the submitted report file.
-    let file = Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsIFile);
-    file.initWithPath(Services.crashmanager._submittedDumpsDir);
-    file.append(remoteID + ".txt");
-    ok(file.exists(), "Submitted report file should exist");
-    file.remove(false);
-  }
-
-  let extra = getPropertyBagValue(propBag, "extra");
-  ok(extra instanceof Ci.nsIPropertyBag, "Extra data should be property bag");
-
-  let val = getPropertyBagValue(extra, "PluginUserComment");
-  if (config.comment) {
-    is(val, config.comment,
-       "Comment in extra data should match comment in textbox");
-  } else {
-    ok(val === undefined,
-       "Comment should be absent from extra data when textbox is empty");
-  }
-
-  val = getPropertyBagValue(extra, "PluginContentURL");
-  if (config.urlOptIn) {
-    is(val, gBrowser.currentURI.spec,
-       "URL in extra data should match browser URL when opt-in checked");
-  } else {
-    ok(val === undefined,
-       "URL should be absent from extra data when opt-in not checked");
-  }
-
-  return true;
-}
-
-function getPropertyBagValue(bag, key) {
-  try {
-    var val = bag.getProperty(key);
-  } catch (e) {
-    if (e.result != Cr.NS_ERROR_FAILURE) {
-      throw e;
-    }
-  }
-  return val;
-}
diff --git a/browser/base/content/test/plugins/xbl/browser_pluginCrashReportNonDeterminism.js b/browser/base/content/test/plugins/xbl/browser_pluginCrashReportNonDeterminism.js
deleted file mode 100644
index fee1c5dcaa8e..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_pluginCrashReportNonDeterminism.js
+++ /dev/null
@@ -1,270 +0,0 @@
-/* import-globals-from ../head.js */
-
-/* Any copyright is dedicated to the Public Domain.
- * http://creativecommons.org/publicdomain/zero/1.0/ */
-
-ChromeUtils.import("resource://gre/modules/PromiseUtils.jsm");
-
-/**
- * With e10s, plugins must run in their own process. This means we have
- * three processes at a minimum when we're running a plugin:
- *
- * 1) The main browser, or "chrome" process
- * 2) The content process hosting the plugin instance
- * 3) The plugin process
- *
- * If the plugin process crashes, we cannot be sure if the chrome process
- * will hear about it first, or the content process will hear about it
- * first. Because of how IPC works, that's really up to the operating system,
- * and we assume any guarantees about it, so we have to account for both
- * possibilities.
- *
- * This test exercises the browser's reaction to both possibilities.
- */
-
-const CRASH_URL = "http://example.com/browser/browser/base/content/test/plugins/plugin_crashCommentAndURL.html";
-const CRASHED_MESSAGE = "BrowserPlugins:NPAPIPluginProcessCrashed";
-
-/**
- * In order for our test to work, we need to be able to put a plugin
- * in a very specific state. Specifically, we need it to match the
- * :-moz-handler-crashed pseudoselector. The only way I can find to
- * do that is by actually crashing the plugin. So we wait for the
- * plugin to crash and show the "please" state (since that will
- * only show if both the message from the parent has been received
- * AND the PluginCrashed event has fired).
- *
- * Once in that state, we try to rewind the clock a little bit - we clear
- * out the crashData cache in the PluginContent with a message, and we also
- * override the pluginFallbackState of the <object> to fool PluginContent
- * into believing that the plugin is in a particular state.
- *
- * @param browser
- *        The browser that has loaded the CRASH_URL that we need to
- *        prepare to be in the special state.
- * @param pluginFallbackState
- *        The value we should override the <object>'s pluginFallbackState
- *        with.
- * @return Promise
- *        The Promise resolves when the plugin has officially been put into
- *        the crash reporter state, and then "rewound" to have the "status"
- *        attribute of the statusDiv removed. The resolved Promise returns
- *        the run ID for the crashed plugin. It rejects if we never get into
- *        the crash reporter state.
- */
-function preparePlugin(browser, pluginFallbackState) {
-  return ContentTask.spawn(browser, pluginFallbackState, async function(contentPluginFallbackState) {
-    let plugin = content.document.getElementById("plugin");
-    plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    // CRASH_URL will load a plugin that crashes immediately. We
-    // wait until the plugin has finished being put into the crash
-    // state.
-    let statusDiv;
-    await ContentTaskUtils.waitForCondition(() => {
-      statusDiv = plugin.ownerDocument
-                        .getAnonymousElementByAttribute(plugin, "anonid",
-                                                        "submitStatus");
-      return statusDiv && statusDiv.getAttribute("status") == "please";
-    }, "Timed out waiting for plugin to be in crash report state");
-
-    // "Rewind", by wiping out the status attribute...
-    statusDiv.removeAttribute("status");
-    // Somehow, I'm able to get away with overriding the getter for
-    // this XPCOM object. Probably because I've got chrome privledges.
-    Object.defineProperty(plugin, "pluginFallbackType", {
-      get() {
-        return contentPluginFallbackState;
-      },
-    });
-    return plugin.runID;
-  }).then((runID) => {
-    browser.messageManager.sendAsyncMessage("BrowserPlugins:Test:ClearCrashData");
-    return runID;
-  });
-}
-
-// Bypass click-to-play
-setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED);
-
-// Deferred promise object used by the test to wait for the crash handler
-let crashDeferred = null;
-
-// Clear out any minidumps we create from plugins - we really don't care
-// about them.
-let crashObserver = (subject, topic, data) => {
-  if (topic != "plugin-crashed") {
-    return;
-  }
-
-  let propBag = subject.QueryInterface(Ci.nsIPropertyBag2);
-  let minidumpID = propBag.getPropertyAsAString("pluginDumpID");
-
-  Services.crashmanager.ensureCrashIsPresent(minidumpID).then(() => {
-    let minidumpDir = Services.dirsvc.get("ProfD", Ci.nsIFile);
-    minidumpDir.append("minidumps");
-
-    let pluginDumpFile = minidumpDir.clone();
-    pluginDumpFile.append(minidumpID + ".dmp");
-
-    let extraFile = minidumpDir.clone();
-    extraFile.append(minidumpID + ".extra");
-
-    ok(pluginDumpFile.exists(), "Found minidump");
-    ok(extraFile.exists(), "Found extra file");
-
-    pluginDumpFile.remove(false);
-    extraFile.remove(false);
-    crashDeferred.resolve();
-  });
-};
-
-Services.obs.addObserver(crashObserver, "plugin-crashed");
-// plugins.testmode will make BrowserPlugins:Test:ClearCrashData work.
-Services.prefs.setBoolPref("plugins.testmode", true);
-registerCleanupFunction(() => {
-  Services.prefs.clearUserPref("plugins.testmode");
-  Services.obs.removeObserver(crashObserver, "plugin-crashed");
-});
-
-/**
- * In this case, the chrome process hears about the crash first.
- */
-add_task(async function testChromeHearsPluginCrashFirst() {
-  // Setup the crash observer promise
-  crashDeferred = PromiseUtils.defer();
-
-  // Open a remote window so that we can run this test even if e10s is not
-  // enabled by default.
-  let win = await BrowserTestUtils.openNewBrowserWindow({remote: true});
-  let browser = win.gBrowser.selectedBrowser;
-
-  BrowserTestUtils.loadURI(browser, CRASH_URL);
-  await BrowserTestUtils.browserLoaded(browser);
-
-  // In this case, we want the <object> to match the -moz-handler-crashed
-  // pseudoselector, but we want it to seem still active, because the
-  // content process is not yet supposed to know that the plugin has
-  // crashed.
-  let runID = await preparePlugin(browser,
-                                  Ci.nsIObjectLoadingContent.PLUGIN_ACTIVE);
-
-  // Send the message down to PluginContent.jsm saying that the plugin has
-  // crashed, and that we have a crash report.
-  let mm = browser.messageManager;
-  mm.sendAsyncMessage(CRASHED_MESSAGE,
-                      { pluginName: "", runID, state: "please" });
-
-  await ContentTask.spawn(browser, null, async function() {
-    // At this point, the content process should have heard the
-    // plugin crash message from the parent, and we are OK to emit
-    // the PluginCrashed event.
-    let plugin = content.document.getElementById("plugin");
-    plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    let statusDiv = plugin.ownerDocument
-                          .getAnonymousElementByAttribute(plugin, "anonid",
-                                                          "submitStatus");
-
-    if (statusDiv.getAttribute("status") == "please") {
-      Assert.ok(false, "Did not expect plugin to be in crash report mode yet.");
-      return;
-    }
-
-    // Now we need the plugin to seem crashed to PluginContent.jsm, without
-    // actually crashing the plugin again. We hack around this by overriding
-    // the pluginFallbackType again.
-    Object.defineProperty(plugin, "pluginFallbackType", {
-      get() {
-        return Ci.nsIObjectLoadingContent.PLUGIN_CRASHED;
-      },
-    });
-
-    let event = new content.PluginCrashedEvent("PluginCrashed", {
-      pluginName: "",
-      pluginDumpID: "",
-      browserDumpID: "",
-      submittedCrashReport: false,
-      bubbles: true,
-      cancelable: true,
-    });
-
-    plugin.dispatchEvent(event);
-    Assert.equal(statusDiv.getAttribute("status"), "please",
-      "Should have been showing crash report UI");
-  });
-  await BrowserTestUtils.closeWindow(win);
-  await crashDeferred.promise;
-});
-
-/**
- * In this case, the content process hears about the crash first.
- */
-add_task(async function testContentHearsCrashFirst() {
-  // Setup the crash observer promise
-  crashDeferred = PromiseUtils.defer();
-
-  // Open a remote window so that we can run this test even if e10s is not
-  // enabled by default.
-  let win = await BrowserTestUtils.openNewBrowserWindow({remote: true});
-  let browser = win.gBrowser.selectedBrowser;
-
-  BrowserTestUtils.loadURI(browser, CRASH_URL);
-  await BrowserTestUtils.browserLoaded(browser);
-
-  // In this case, we want the <object> to match the -moz-handler-crashed
-  // pseudoselector, and we want the plugin to seem crashed, since the
-  // content process in this case has heard about the crash first.
-  let runID = await preparePlugin(browser,
-                                  Ci.nsIObjectLoadingContent.PLUGIN_CRASHED);
-
-  await ContentTask.spawn(browser, null, async function() {
-    // At this point, the content process has not yet heard from the
-    // parent about the crash report. Let's ensure that by making sure
-    // we're not showing the plugin crash report UI.
-    let plugin = content.document.getElementById("plugin");
-    plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    let statusDiv = plugin.ownerDocument
-                          .getAnonymousElementByAttribute(plugin, "anonid",
-                                                          "submitStatus");
-
-    if (statusDiv.getAttribute("status") == "please") {
-      Assert.ok(false, "Did not expect plugin to be in crash report mode yet.");
-    }
-
-    let event = new content.PluginCrashedEvent("PluginCrashed", {
-      pluginName: "",
-      pluginDumpID: "",
-      browserDumpID: "",
-      submittedCrashReport: false,
-      bubbles: true,
-      cancelable: true,
-    });
-
-    plugin.dispatchEvent(event);
-
-    Assert.notEqual(statusDiv.getAttribute("status"), "please",
-      "Should not yet be showing crash report UI");
-  });
-
-  // Now send the message down to PluginContent.jsm that the plugin has
-  // crashed...
-  let mm = browser.messageManager;
-  mm.sendAsyncMessage(CRASHED_MESSAGE,
-                      { pluginName: "", runID, state: "please"});
-
-  await ContentTask.spawn(browser, null, async function() {
-    // At this point, the content process will have heard the message
-    // from the parent and reacted to it. We should be showing the plugin
-    // crash report UI now.
-    let plugin = content.document.getElementById("plugin");
-    plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    let statusDiv = plugin.ownerDocument
-                          .getAnonymousElementByAttribute(plugin, "anonid",
-                                                          "submitStatus");
-
-    Assert.equal(statusDiv.getAttribute("status"), "please",
-      "Should have been showing crash report UI");
-  });
-
-  await BrowserTestUtils.closeWindow(win);
-  await crashDeferred.promise;
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_plugin_reloading.js b/browser/base/content/test/plugins/xbl/browser_plugin_reloading.js
deleted file mode 100644
index deec8844396c..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_plugin_reloading.js
+++ /dev/null
@@ -1,86 +0,0 @@
-/* import-globals-from ../head.js */
-
-var gTestRoot = getRootDirectory(gTestPath).replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gPluginHost = Cc["@mozilla.org/plugin/host;1"].getService(Ci.nsIPluginHost);
-var gTestBrowser = null;
-
-function updateAllTestPlugins(aState) {
-  setTestPluginEnabledState(aState, "Test Plug-in");
-  setTestPluginEnabledState(aState, "Second Test Plug-in");
-}
-
-add_task(async function() {
-  registerCleanupFunction(async function() {
-    clearAllPluginPermissions();
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    await asyncSetAndUpdateBlocklist(gTestRoot + "blockNoPlugins.xml", gTestBrowser);
-    resetBlocklist();
-    gTestBrowser = null;
-    gBrowser.removeCurrentTab();
-    window.focus();
-  });
-});
-
-add_task(async function() {
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-  gTestBrowser = gBrowser.selectedBrowser;
-
-  Services.prefs.setBoolPref("extensions.blocklist.suppressUI", true);
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-
-  updateAllTestPlugins(Ci.nsIPluginTag.STATE_CLICKTOPLAY);
-
-  // Prime the blocklist service, the remote service doesn't launch on startup.
-  await promiseTabLoadEvent(gBrowser.selectedTab, "data:text/html,<html></html>");
-
-  await asyncSetAndUpdateBlocklist(gTestRoot + "blockNoPlugins.xml", gTestBrowser);
-});
-
-// Tests that a click-to-play plugin retains its activated state upon reloading
-add_task(async function() {
-  clearAllPluginPermissions();
-
-  updateAllTestPlugins(Ci.nsIPluginTag.STATE_CLICKTOPLAY);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let notification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(notification, "Test 1, Should have a click-to-play notification");
-
-  let pluginInfo = await promiseForPluginInfo("test");
-  is(pluginInfo.pluginFallbackType, Ci.nsIObjectLoadingContent.PLUGIN_CLICK_TO_PLAY,
-     "Test 2, plugin fallback type should be PLUGIN_CLICK_TO_PLAY");
-
-  // run the plugin
-  await promisePlayObject("test");
-
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  pluginInfo = await promiseForPluginInfo("test");
-  is(pluginInfo.displayedType, Ci.nsIObjectLoadingContent.TYPE_PLUGIN, "Test 3, plugin should have started");
-  ok(pluginInfo.activated, "Test 4, plugin node should not be activated");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let plugin = content.document.getElementById("test");
-    let npobj1 = Cu.waiveXrays(plugin).getObjectValue();
-    // eslint-disable-next-line no-self-assign
-    plugin.src = plugin.src;
-    let pluginsDiffer = false;
-    try {
-      Cu.waiveXrays(plugin).checkObjectValue(npobj1);
-    } catch (e) {
-      pluginsDiffer = true;
-    }
-
-     Assert.ok(pluginsDiffer, "Test 5, plugins differ.");
-  });
-
-  pluginInfo = await promiseForPluginInfo("test");
-  ok(pluginInfo.activated, "Test 6, Plugin should have retained activated state.");
-  is(pluginInfo.displayedType, Ci.nsIObjectLoadingContent.TYPE_PLUGIN, "Test 7, plugin should have started");
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_pluginnotification.js b/browser/base/content/test/plugins/xbl/browser_pluginnotification.js
deleted file mode 100644
index 8c4bc8f5e5ec..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_pluginnotification.js
+++ /dev/null
@@ -1,480 +0,0 @@
-/* import-globals-from ../head.js */
-
-var gTestRoot = getRootDirectory(gTestPath).replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-var gPluginHost = Cc["@mozilla.org/plugin/host;1"].getService(Ci.nsIPluginHost);
-var gTestBrowser = null;
-
-function updateAllTestPlugins(aState) {
-  setTestPluginEnabledState(aState, "Test Plug-in");
-  setTestPluginEnabledState(aState, "Second Test Plug-in");
-}
-
-add_task(async function() {
-  registerCleanupFunction(async function() {
-    clearAllPluginPermissions();
-    Services.prefs.clearUserPref("plugins.click_to_play");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Test Plug-in");
-    setTestPluginEnabledState(Ci.nsIPluginTag.STATE_ENABLED, "Second Test Plug-in");
-    await asyncSetAndUpdateBlocklist(gTestRoot + "blockNoPlugins.xml", gTestBrowser);
-    resetBlocklist();
-    gTestBrowser = null;
-    gBrowser.removeCurrentTab();
-    window.focus();
-  });
-});
-
-add_task(async function() {
-  gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser);
-  gTestBrowser = gBrowser.selectedBrowser;
-
-  Services.prefs.setBoolPref("extensions.blocklist.suppressUI", true);
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-
-  updateAllTestPlugins(Ci.nsIPluginTag.STATE_CLICKTOPLAY);
-
-  // Prime the blocklist service, the remote service doesn't launch on startup.
-  await promiseTabLoadEvent(gBrowser.selectedTab, "data:text/html,<html></html>");
-
-  await asyncSetAndUpdateBlocklist(gTestRoot + "blockNoPlugins.xml", gTestBrowser);
-});
-
-// Tests a page with an unknown plugin in it.
-add_task(async function() {
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_unknown.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let pluginInfo = await promiseForPluginInfo("unknown");
-  is(pluginInfo.pluginFallbackType, Ci.nsIObjectLoadingContent.PLUGIN_UNSUPPORTED,
-     "Test 1a, plugin fallback type should be PLUGIN_UNSUPPORTED");
-});
-
-// Test that the doorhanger is shown when the user clicks on the overlay
-// after having previously blocked the plugin.
-add_task(async function() {
-  updateAllTestPlugins(Ci.nsIPluginTag.STATE_CLICKTOPLAY);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  await promisePopupNotification("click-to-play-plugins");
-
-  let pluginInfo = await promiseForPluginInfo("test");
-  ok(!pluginInfo.activated, "Plugin should not be activated");
-
-  // Simulate clicking the "Allow" button.
-  let notification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-
-  await promiseForNotificationShown(notification);
-
-  PopupNotifications.panel.firstElementChild.button.click();
-
-  pluginInfo = await promiseForPluginInfo("test");
-  ok(pluginInfo.activated, "Plugin should be activated");
-
-  // Simulate clicking the "Block" button.
-  await promiseForNotificationShown(notification);
-
-  PopupNotifications.panel.firstElementChild.secondaryButton.click();
-
-  pluginInfo = await promiseForPluginInfo("test");
-  ok(!pluginInfo.activated, "Plugin should not be activated");
-
-  let browserLoaded = BrowserTestUtils.browserLoaded(gTestBrowser);
-  gTestBrowser.reload();
-  await browserLoaded;
-  notification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-
-  // Simulate clicking the overlay
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let bounds = doc.getAnonymousElementByAttribute(plugin, "anonid", "main").getBoundingClientRect();
-    let left = (bounds.left + bounds.right) / 2;
-    let top = (bounds.top + bounds.bottom) / 2;
-    let utils = content.windowUtils;
-    utils.sendMouseEvent("mousedown", left, top, 0, 1, 0, false, 0, 0);
-    utils.sendMouseEvent("mouseup", left, top, 0, 1, 0, false, 0, 0);
-  });
-
-  ok(!notification.dismissed, "A plugin notification should be shown.");
-
-  clearAllPluginPermissions();
-});
-
-// Tests that going back will reshow the notification for click-to-play plugins
-add_task(async function() {
-  updateAllTestPlugins(Ci.nsIPluginTag.STATE_CLICKTOPLAY);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  await promisePopupNotification("click-to-play-plugins");
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, "data:text/html,<html>hi</html>");
-
-  // make sure the notification is gone
-  let notification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(!notification, "Test 11b, Should not have a click-to-play notification");
-
-  gTestBrowser.webNavigation.goBack();
-
-  await promisePopupNotification("click-to-play-plugins");
-});
-
-// Tests that the "Allow Always" permission works for click-to-play plugins
-add_task(async function() {
-  updateAllTestPlugins(Ci.nsIPluginTag.STATE_CLICKTOPLAY);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  await promisePopupNotification("click-to-play-plugins");
-
-  let pluginInfo = await promiseForPluginInfo("test");
-  ok(!pluginInfo.activated, "Test 12a, Plugin should not be activated");
-
-  // Simulate clicking the "Allow" button.
-  let notification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-
-  await promiseForNotificationShown(notification);
-
-  PopupNotifications.panel.firstElementChild.button.click();
-
-  pluginInfo = await promiseForPluginInfo("test");
-  ok(pluginInfo.activated, "Test 12a, Plugin should be activated");
-});
-
-// Test that the "Always" permission, when set for just the Test plugin,
-// does not also allow the Second Test plugin.
-add_task(async function() {
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_two_types.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  await promisePopupNotification("click-to-play-plugins");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let test = content.document.getElementById("test");
-    let secondtestA = content.document.getElementById("secondtestA");
-    let secondtestB = content.document.getElementById("secondtestB");
-    Assert.ok(test.activated && !secondtestA.activated && !secondtestB.activated,
-      "Content plugins are set up");
-  });
-
-  clearAllPluginPermissions();
-});
-
-// Tests that the plugin's "activated" property is true for working plugins
-// with click-to-play disabled.
-add_task(async function() {
-  updateAllTestPlugins(Ci.nsIPluginTag.STATE_ENABLED);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test2.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let pluginInfo = await promiseForPluginInfo("test1");
-  ok(pluginInfo.activated, "Test 14, Plugin should be activated");
-});
-
-// Tests that the overlay is shown instead of alternate content when
-// plugins are click to play.
-add_task(async function() {
-  updateAllTestPlugins(Ci.nsIPluginTag.STATE_CLICKTOPLAY);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_alternate_content.html");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let mainBox = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-    Assert.ok(!!mainBox, "Test 15, Plugin overlay should exist");
-  });
-});
-
-// Tests that mContentType is used for click-to-play plugins, and not the
-// inspected type.
-add_task(async function() {
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_bug749455.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let notification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(notification, "Test 17, Should have a click-to-play notification");
-});
-
-// Tests that clicking the icon of the overlay activates the doorhanger
-add_task(async function() {
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  await asyncSetAndUpdateBlocklist(gTestRoot + "blockNoPlugins.xml", gTestBrowser);
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let pluginInfo = await promiseForPluginInfo("test");
-  ok(!pluginInfo.activated, "Test 18g, Plugin should not be activated");
-
-  ok(PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed,
-     "Test 19a, Doorhanger should start out dismissed");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let icon = doc.getAnonymousElementByAttribute(plugin, "class", "icon");
-    let bounds = icon.getBoundingClientRect();
-    let left = (bounds.left + bounds.right) / 2;
-    let top = (bounds.top + bounds.bottom) / 2;
-    let utils = content.windowUtils;
-    utils.sendMouseEvent("mousedown", left, top, 0, 1, 0, false, 0, 0);
-    utils.sendMouseEvent("mouseup", left, top, 0, 1, 0, false, 0, 0);
-  });
-
-  let condition = () => !PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed;
-  await promiseForCondition(condition);
-});
-
-// Tests that clicking the text of the overlay activates the plugin
-add_task(async function() {
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let pluginInfo = await promiseForPluginInfo("test");
-  ok(!pluginInfo.activated, "Test 18g, Plugin should not be activated");
-
-  ok(PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed,
-     "Test 19c, Doorhanger should start out dismissed");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let text = doc.getAnonymousElementByAttribute(plugin, "class", "msg msgClickToPlay");
-    let bounds = text.getBoundingClientRect();
-    let left = (bounds.left + bounds.right) / 2;
-    let top = (bounds.top + bounds.bottom) / 2;
-    let utils = content.windowUtils;
-    utils.sendMouseEvent("mousedown", left, top, 0, 1, 0, false, 0, 0);
-    utils.sendMouseEvent("mouseup", left, top, 0, 1, 0, false, 0, 0);
-  });
-
-  let condition = () => !PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed;
-  await promiseForCondition(condition);
-});
-
-// Tests that clicking the box of the overlay activates the doorhanger
-// (just to be thorough)
-add_task(async function() {
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let pluginInfo = await promiseForPluginInfo("test");
-  ok(!pluginInfo.activated, "Test 18g, Plugin should not be activated");
-
-  ok(PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed,
-     "Test 19e, Doorhanger should start out dismissed");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let utils = content.windowUtils;
-    utils.sendMouseEvent("mousedown", 50, 50, 0, 1, 0, false, 0, 0);
-    utils.sendMouseEvent("mouseup", 50, 50, 0, 1, 0, false, 0, 0);
-  });
-
-  let condition = () => !PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed &&
-    PopupNotifications.panel.firstElementChild;
-  await promiseForCondition(condition);
-  PopupNotifications.panel.firstElementChild.button.click();
-
-  pluginInfo = await promiseForPluginInfo("test");
-  ok(pluginInfo.activated, "Test 19e, Plugin should not be activated");
-
-  clearAllPluginPermissions();
-});
-
-// Tests that a plugin in a div that goes from style="display: none" to
-// "display: block" can be clicked to activate.
-add_task(async function() {
-  updateAllTestPlugins(Ci.nsIPluginTag.STATE_CLICKTOPLAY);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_hidden_to_visible.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let notification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(notification, "Test 20a, Should have a click-to-play notification");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-    Assert.ok(!!overlay, "Test 20a, Plugin overlay should exist");
-  });
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let mainBox = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-    let overlayRect = mainBox.getBoundingClientRect();
-    Assert.ok(overlayRect.width == 0 && overlayRect.height == 0,
-      "Test 20a, plugin should have an overlay with 0px width and height");
-  });
-
-  let pluginInfo = await promiseForPluginInfo("test");
-  ok(!pluginInfo.activated, "Test 20b, plugin should not be activated");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let div = doc.getElementById("container");
-    Assert.equal(div.style.display, "none",
-      "Test 20b, container div should be display: none");
-  });
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let div = doc.getElementById("container");
-    div.style.display = "block";
-  });
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let mainBox = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
-    let overlayRect = mainBox.getBoundingClientRect();
-    Assert.ok(overlayRect.width == 200 && overlayRect.height == 200,
-      "Test 20c, plugin should have overlay dims of 200px");
-  });
-
-  pluginInfo = await promiseForPluginInfo("test");
-  ok(!pluginInfo.activated, "Test 20b, plugin should not be activated");
-
-  ok(notification.dismissed, "Test 20c, Doorhanger should start out dismissed");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let bounds = plugin.getBoundingClientRect();
-    let left = (bounds.left + bounds.right) / 2;
-    let top = (bounds.top + bounds.bottom) / 2;
-    let utils = content.windowUtils;
-    utils.sendMouseEvent("mousedown", left, top, 0, 1, 0, false, 0, 0);
-    utils.sendMouseEvent("mouseup", left, top, 0, 1, 0, false, 0, 0);
-  });
-
-  let condition = () => !notification.dismissed && !!PopupNotifications.panel.firstElementChild;
-  await promiseForCondition(condition);
-  PopupNotifications.panel.firstElementChild.button.click();
-
-  pluginInfo = await promiseForPluginInfo("test");
-  ok(pluginInfo.activated, "Test 20c, plugin should be activated");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    let overlayRect = doc.getAnonymousElementByAttribute(plugin, "anonid", "main").getBoundingClientRect();
-    Assert.ok(overlayRect.width == 0 && overlayRect.height == 0,
-      "Test 20c, plugin should have overlay dims of 0px");
-  });
-
-  clearAllPluginPermissions();
-});
-
-// Tests that a click-to-play plugin resets its activated state when changing types
-add_task(async function() {
-  clearAllPluginPermissions();
-
-  updateAllTestPlugins(Ci.nsIPluginTag.STATE_CLICKTOPLAY);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let notification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(notification, "Test 22, Should have a click-to-play notification");
-
-  // Plugin should start as CTP
-  let pluginInfo = await promiseForPluginInfo("test");
-  is(pluginInfo.pluginFallbackType, Ci.nsIObjectLoadingContent.PLUGIN_CLICK_TO_PLAY,
-     "Test 23, plugin fallback type should be PLUGIN_CLICK_TO_PLAY");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    plugin.type = null;
-    // We currently don't properly change state just on type change,
-    // so rebind the plugin to tree. bug 767631
-    plugin.parentNode.appendChild(plugin);
-  });
-
-  pluginInfo = await promiseForPluginInfo("test");
-  is(pluginInfo.displayedType, Ci.nsIObjectLoadingContent.TYPE_NULL, "Test 23, plugin should be TYPE_NULL");
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let doc = content.document;
-    let plugin = doc.getElementById("test");
-    plugin.type = "application/x-test";
-    plugin.parentNode.appendChild(plugin);
-  });
-
-  pluginInfo = await promiseForPluginInfo("test");
-  is(pluginInfo.displayedType, Ci.nsIObjectLoadingContent.TYPE_NULL, "Test 23, plugin should be TYPE_NULL");
-  is(pluginInfo.pluginFallbackType, Ci.nsIObjectLoadingContent.PLUGIN_CLICK_TO_PLAY,
-     "Test 23, plugin fallback type should be PLUGIN_CLICK_TO_PLAY");
-  ok(!pluginInfo.activated, "Test 23, plugin node should not be activated");
-});
-
-// Plugin sync removal test. Note this test produces a notification drop down since
-// the plugin we add has zero dims.
-add_task(async function() {
-  updateAllTestPlugins(Ci.nsIPluginTag.STATE_CLICKTOPLAY);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_syncRemoved.html");
-
-  // Maybe there some better trick here, we need to wait for the page load, then
-  // wait for the js to execute in the page.
-  await waitForMs(500);
-
-  let notification = PopupNotifications.getNotification("click-to-play-plugins");
-  ok(notification, "Test 25: There should be a plugin notification even if the plugin was immediately removed");
-  ok(notification.dismissed, "Test 25: The notification should be dismissed by default");
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, "data:text/html,<html>hi</html>");
-});
-
-// Tests a page with a blocked plugin in it and make sure the infoURL property
-// the blocklist file gets used.
-add_task(async function() {
-  clearAllPluginPermissions();
-
-  await asyncSetAndUpdateBlocklist(gTestRoot + "blockPluginInfoURL.xml", gTestBrowser);
-
-  await promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
-
-  // Work around for delayed PluginBindingAttached
-  await promiseUpdatePluginBindings(gTestBrowser);
-
-  let notification = PopupNotifications.getNotification("click-to-play-plugins");
-
-  // Since the plugin notification is dismissed by default, reshow it.
-  await promiseForNotificationShown(notification);
-
-  let pluginInfo = await promiseForPluginInfo("test");
-  is(pluginInfo.pluginFallbackType, Ci.nsIObjectLoadingContent.PLUGIN_BLOCKLISTED,
-     "Test 26, plugin fallback type should be PLUGIN_BLOCKLISTED");
-  ok(!pluginInfo.activated, "Plugin should be activated.");
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_private_browsing_eme_persistent_state.js b/browser/base/content/test/plugins/xbl/browser_private_browsing_eme_persistent_state.js
deleted file mode 100644
index f8b08fee5543..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_private_browsing_eme_persistent_state.js
+++ /dev/null
@@ -1,44 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-/*
- * This test ensures that navigator.requestMediaKeySystemAccess() requests
- * to run EME with persistent state are rejected in private browsing windows.
- * Bug 1334111.
- */
-
-const TEST_URL =
-  getRootDirectory(gTestPath).replace("chrome://mochitests/content",
-  "https://example.com") + "empty_file.html";
-
-async function isEmePersistentStateSupported(mode) {
-  let win = await BrowserTestUtils.openNewBrowserWindow(mode);
-  let tab = await BrowserTestUtils.openNewForegroundTab(win.gBrowser, TEST_URL);
-  let persistentStateSupported = await ContentTask.spawn(tab.linkedBrowser, {}, async function() {
-    try {
-      let config = [{
-        initDataTypes: ["webm"],
-        videoCapabilities: [{contentType: 'video/webm; codecs="vp9"'}],
-        persistentState: "required",
-      }];
-      await content.navigator.requestMediaKeySystemAccess("org.w3.clearkey", config);
-    } catch (ex) {
-      return false;
-    }
-    return true;
-  });
-
-  await BrowserTestUtils.closeWindow(win);
-
-  return persistentStateSupported;
-}
-
-add_task(async function test() {
-  is(await isEmePersistentStateSupported({private: true}),
-     false,
-     "EME persistentState should *NOT* be supported in private browsing window.");
-  is(await isEmePersistentStateSupported({private: false}),
-     true,
-     "EME persistentState *SHOULD* be supported in non private browsing window.");
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_private_clicktoplay.js b/browser/base/content/test/plugins/xbl/browser_private_clicktoplay.js
deleted file mode 100644
index c49fcfb125c8..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_private_clicktoplay.js
+++ /dev/null
@@ -1,230 +0,0 @@
-/* import-globals-from ../head.js */
-
-var rootDir = getRootDirectory(gTestPath);
-const gTestRoot = rootDir;
-const gHttpTestRoot = rootDir.replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
-
-var gTestBrowser = null;
-var gNextTest = null;
-var gPluginHost = Cc["@mozilla.org/plugin/host;1"].getService(Ci.nsIPluginHost);
-
-ChromeUtils.import("resource://gre/modules/Services.jsm");
-
-var gPrivateWindow = null;
-var gPrivateBrowser = null;
-
-function finishTest() {
-  clearAllPluginPermissions();
-  gBrowser.removeCurrentTab();
-  if (gPrivateWindow) {
-    gPrivateWindow.close();
-  }
-  window.focus();
-}
-
-let createPrivateWindow = async function createPrivateWindow(url) {
-  gPrivateWindow = await BrowserTestUtils.openNewBrowserWindow({private: true});
-  ok(!!gPrivateWindow, "should have created a private window.");
-  gPrivateBrowser = gPrivateWindow.getBrowser().selectedBrowser;
-
-  BrowserTestUtils.loadURI(gPrivateBrowser, url);
-  await BrowserTestUtils.browserLoaded(gPrivateBrowser, false, url);
-  info("loaded " + url);
-};
-
-add_task(async function test() {
-  registerCleanupFunction(function() {
-    clearAllPluginPermissions();
-    getTestPlugin().enabledState = Ci.nsIPluginTag.STATE_ENABLED;
-    getTestPlugin("Second Test Plug-in").enabledState = Ci.nsIPluginTag.STATE_ENABLED;
-  });
-
-  let newTab = BrowserTestUtils.addTab(gBrowser);
-  gBrowser.selectedTab = newTab;
-  gTestBrowser = gBrowser.selectedBrowser;
-  let promise = BrowserTestUtils.browserLoaded(gTestBrowser);
-
-  Services.prefs.setBoolPref("plugins.click_to_play", true);
-  getTestPlugin().enabledState = Ci.nsIPluginTag.STATE_CLICKTOPLAY;
-  getTestPlugin("Second Test Plug-in").enabledState = Ci.nsIPluginTag.STATE_CLICKTOPLAY;
-  await promise;
-});
-
-add_task(async function test1a() {
-  await createPrivateWindow(gHttpTestRoot + "plugin_test.html");
-});
-
-add_task(async function test1b() {
-  let popupNotification = gPrivateWindow.PopupNotifications.getNotification("click-to-play-plugins", gPrivateBrowser);
-  ok(popupNotification, "Test 1b, Should have a click-to-play notification");
-
-  await ContentTask.spawn(gPrivateBrowser, null, function() {
-    let plugin = content.document.getElementById("test");
-    let objLoadingContent = plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    ok(!objLoadingContent.activated, "Test 1b, Plugin should not be activated");
-  });
-
-  // Check the button status
-  let promiseShown = BrowserTestUtils.waitForEvent(gPrivateWindow.PopupNotifications.panel,
-                                                   "Shown");
-  popupNotification.reshow();
-
-  await promiseShown;
-  is(gPrivateWindow.PopupNotifications.panel.firstElementChild.checkbox.hidden, true, "'Remember' checkbox should be hidden in private windows");
-
-  let promises = [
-    BrowserTestUtils.browserLoaded(gTestBrowser, false, gHttpTestRoot + "plugin_test.html"),
-    BrowserTestUtils.waitForEvent(window, "activate"),
-  ];
-  gPrivateWindow.close();
-  BrowserTestUtils.loadURI(gTestBrowser, gHttpTestRoot + "plugin_test.html");
-  await Promise.all(promises);
-  await SimpleTest.promiseFocus(window);
-});
-
-add_task(async function test2a() {
-  // enable test plugin on this site
-  let popupNotification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(popupNotification, "Test 2a, Should have a click-to-play notification");
-
-  await ContentTask.spawn(gTestBrowser, null, function() {
-    let plugin = content.document.getElementById("test");
-    let objLoadingContent = plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    ok(!objLoadingContent.activated, "Test 2a, Plugin should not be activated");
-  });
-
-  // Simulate clicking the "Allow Now" button.
-  let promiseShown = BrowserTestUtils.waitForEvent(PopupNotifications.panel,
-                                                   "Shown");
-  popupNotification.reshow();
-  await promiseShown;
-
-  PopupNotifications.panel.firstElementChild.button.click();
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let plugin = content.document.getElementById("test");
-    let objLoadingContent = plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    let condition = () => objLoadingContent.activated;
-    await ContentTaskUtils.waitForCondition(condition, "Test 2a, Waited too long for plugin to activate");
-  });
-});
-
-add_task(async function test2c() {
-  let topicObserved = TestUtils.topicObserved("PopupNotifications-updateNotShowing");
-  await createPrivateWindow(gHttpTestRoot + "plugin_test.html");
-  await topicObserved;
-
-  let popupNotification = gPrivateWindow.PopupNotifications.getNotification("click-to-play-plugins", gPrivateBrowser);
-  ok(popupNotification, "Test 2c, Should have a click-to-play notification");
-
-  await ContentTask.spawn(gPrivateBrowser, null, function() {
-    let plugin = content.document.getElementById("test");
-    let objLoadingContent = plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    ok(objLoadingContent.activated, "Test 2c, Plugin should be activated");
-  });
-
-  // Check the button status
-  let promiseShown = BrowserTestUtils.waitForEvent(gPrivateWindow.PopupNotifications.panel,
-                                                   "Shown");
-  popupNotification.reshow();
-  await promiseShown;
-  is(gPrivateWindow.PopupNotifications.panel.firstElementChild.secondaryButton.hidden, true,
-     "Test 2c, Activated plugin in a private window should not have visible 'Block' button.");
-  is(gPrivateWindow.PopupNotifications.panel.firstElementChild.checkbox.hidden, true,
-     "Test 2c, Activated plugin in a private window should not have visible 'Remember' checkbox.");
-
-  clearAllPluginPermissions();
-
-  let promises = [
-    BrowserTestUtils.browserLoaded(gTestBrowser, false, gHttpTestRoot + "plugin_test.html"),
-    BrowserTestUtils.waitForEvent(window, "activate"),
-  ];
-  gPrivateWindow.close();
-  BrowserTestUtils.loadURI(gTestBrowser, gHttpTestRoot + "plugin_test.html");
-  await Promise.all(promises);
-  await SimpleTest.promiseFocus(window);
-});
-
-add_task(async function test3a() {
-  // enable test plugin on this site
-  let popupNotification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
-  ok(popupNotification, "Test 3a, Should have a click-to-play notification");
-
-  await ContentTask.spawn(gTestBrowser, null, function() {
-    let plugin = content.document.getElementById("test");
-    let objLoadingContent = plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    ok(!objLoadingContent.activated, "Test 3a, Plugin should not be activated");
-  });
-
-  // Simulate clicking the "Allow" button.
-  let promiseShown = BrowserTestUtils.waitForEvent(PopupNotifications.panel,
-                                                   "Shown");
-  popupNotification.reshow();
-  await promiseShown;
-  PopupNotifications.panel.firstElementChild.button.click();
-
-  await ContentTask.spawn(gTestBrowser, null, async function() {
-    let plugin = content.document.getElementById("test");
-    let objLoadingContent = plugin.QueryInterface(Ci.nsIObjectLoadingContent);
-    let condition = () => objLoadingContent.activated;
-    await ContentTaskUtils.waitForCondition(condition, "Test 3a, Waited too long for plugin to activate");
-  });
-});
-
-add_task(async function test3c() {
-  let topicObserved = TestUtils.topicObserved("PopupNotifications-updateNotShowing");
-  await createPrivateWindow(gHttpTestRoot + "plugin_test.html");
-  await topicObserved;
-
-  let popupNotification = gPrivateWindow.PopupNotifications.getNotification("click-to-play-plugins", gPrivateBrowser);
-  ok(popupNotification, "Test 3c, Should have a click-to-play notification");
-
-  // Check the button status
-  let promiseShown = BrowserTestUtils.waitForEvent(gPrivateWindow.PopupNotifications.panel,
-                                                   "Shown");
-  popupNotification.reshow();
-  await promiseShown;
-  is(gPrivateWindow.PopupNotifications.panel.firstElementChild.secondaryButton.hidden, true,
-     "Test 2c, Activated plugin in a private window should not have visible 'Block' button.");
-  is(gPrivateWindow.PopupNotifications.panel.firstElementChild.checkbox.hidden, true,
-     "Test 2c, Activated plugin in a private window should not have visible 'Remember' checkbox.");
-
-  BrowserTestUtils.loadURI(gPrivateBrowser, gHttpTestRoot + "plugin_two_types.html");
-  await BrowserTestUtils.browserLoaded(gPrivateBrowser);
-});
-
-add_task(async function test3d() {
-  let popupNotification = gPrivateWindow.PopupNotifications.getNotification("click-to-play-plugins", gPrivateBrowser);
-  ok(popupNotification, "Test 3d, Should have a click-to-play notification");
-
-  // Check the list item status
-  let promiseShown = BrowserTestUtils.waitForEvent(gPrivateWindow.PopupNotifications.panel,
-                                                   "Shown");
-  popupNotification.reshow();
-  await promiseShown;
-  let doc = gPrivateWindow.document;
-  for (let item of gPrivateWindow.PopupNotifications.panel.firstElementChild.children) {
-    let allowalways = doc.getAnonymousElementByAttribute(item, "anonid", "allowalways");
-    ok(allowalways, "Test 3d, should have list item for allow always");
-    let allownow = doc.getAnonymousElementByAttribute(item, "anonid", "allownow");
-    ok(allownow, "Test 3d, should have list item for allow now");
-    let block = doc.getAnonymousElementByAttribute(item, "anonid", "block");
-    ok(block, "Test 3d, should have list item for block");
-
-    if (item.action.pluginName === "Test") {
-      is(item.value, "allowalways", "Test 3d, Plugin should bet set to 'allow always'");
-      ok(!allowalways.hidden, "Test 3d, Plugin set to 'always allow' should have a visible 'always allow' action.");
-      ok(allownow.hidden, "Test 3d, Plugin set to 'always allow' should have an invisible 'allow now' action.");
-      ok(block.hidden, "Test 3d, Plugin set to 'always allow' should have an invisible 'block' action.");
-    } else if (item.action.pluginName === "Second Test") {
-      is(item.value, "block", "Test 3d, Second plugin should bet set to 'block'");
-      ok(allowalways.hidden, "Test 3d, Plugin set to 'block' should have a visible 'always allow' action.");
-      ok(!allownow.hidden, "Test 3d, Plugin set to 'block' should have a visible 'allow now' action.");
-      ok(!block.hidden, "Test 3d, Plugin set to 'block' should have a visible 'block' action.");
-    } else {
-      ok(false, "Test 3d, Unexpected plugin '" + item.action.pluginName + "'");
-    }
-  }
-
-  finishTest();
-});
diff --git a/browser/base/content/test/plugins/xbl/browser_subframe_access_hidden_plugins.js b/browser/base/content/test/plugins/xbl/browser_subframe_access_hidden_plugins.js
deleted file mode 100644
index 1450728f9f0e..000000000000
--- a/browser/base/content/test/plugins/xbl/browser_subframe_access_hidden_plugins.js
+++ /dev/null
@@ -1,74 +0,0 @@
-/* import-globals-from ../head.js */
-
-"use strict";
-
-const TEST_PLUGIN_NAME = "Test Plug-in";
-const HIDDEN_CTP_PLUGIN_PREF = "plugins.navigator.hidden_ctp_plugin";
-const DOMAIN_1 = "http://example.com";
-const DOMAIN_2 = "http://mochi.test:8888";
-
-/**
- * If a plugin is click-to-play and named in HIDDEN_CTP_PLUGIN_PREF,
- * then the plugin should be hidden in the navigator.plugins list by
- * default. However, if a plugin has been allowed on a top-level
- * document, we should let subframes of that document access
- * navigator.plugins.
- */
-add_task(async function setup() {
-  // We'll make the Test Plugin click-to-play.
-  let originalPluginState = getTestPluginEnabledState();
-  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY);
-  registerCleanupFunction(() => {
-    setTestPluginEnabledState(originalPluginState);
-    clearAllPluginPermissions();
-  });
-
-  // And then make the plugin hidden.
-  await SpecialPowers.pushPrefEnv({
-    set: [[HIDDEN_CTP_PLUGIN_PREF, TEST_PLUGIN_NAME]],
-  });
-});
-
-add_task(async function test_plugin_accessible_in_subframe() {
-  // Let's make it so that DOMAIN_1 allows the test plugin to
-  // be activated. This permission will be cleaned up inside
-  // our registerCleanupFunction when the test ends.
-  let ssm = Services.scriptSecurityManager;
-  let principal = ssm.createCodebasePrincipalFromOrigin(DOMAIN_1);
-  let pluginHost = Cc["@mozilla.org/plugin/host;1"]
-                     .getService(Ci.nsIPluginHost);
-  let permString = pluginHost.getPermissionStringForType("application/x-test");
-  Services.perms.addFromPrincipal(principal, permString,
-                                  Ci.nsIPermissionManager.ALLOW_ACTION,
-                                  Ci.nsIPermissionManager.EXPIRE_NEVER,
-                                  0 /* expireTime */);
-
-  await BrowserTestUtils.withNewTab({
-    gBrowser,
-    url: DOMAIN_1,
-  }, async function(browser) {
-    await ContentTask.spawn(browser, [TEST_PLUGIN_NAME, DOMAIN_2],
-                            async function([pluginName, domain2]) {
-      Assert.ok(content.navigator.plugins[pluginName],
-                "Top-level document should find Test Plugin");
-
-      // Now manually create a subframe hosted at domain2...
-      let subframe = content.document.createElement("iframe");
-      subframe.src = domain2;
-      let loadedPromise = ContentTaskUtils.waitForEvent(subframe, "load");
-      content.document.body.appendChild(subframe);
-      await loadedPromise;
-
-      // Make sure that the HiddenPlugin event never fires in content.
-      let sawEvent = false;
-      addEventListener("HiddenPlugin", function onHiddenPlugin(e) {
-        sawEvent = true;
-        removeEventListener("HiddenPlugin", onHiddenPlugin, true);
-      }, true);
-
-      Assert.ok(subframe.contentWindow.navigator.plugins[pluginName],
-                "Subframe should find Test Plugin");
-      Assert.ok(!sawEvent, "Should not have seen the HiddenPlugin event.");
-    });
-  });
-});
diff --git a/browser/base/content/test/plugins/xbl/empty_file.html b/browser/base/content/test/plugins/xbl/empty_file.html
deleted file mode 100644
index af8440ac16bf..000000000000
--- a/browser/base/content/test/plugins/xbl/empty_file.html
+++ /dev/null
@@ -1,9 +0,0 @@
-<!DOCTYPE html>
-<html>
-  <head>
-    <meta charset="UTF-8">
-  </head>
-  <body>
-    This page is intentionally left blank.
-  </body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_add_dynamically.html b/browser/base/content/test/plugins/xbl/plugin_add_dynamically.html
deleted file mode 100644
index 8ceaaf9b821a..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_add_dynamically.html
+++ /dev/null
@@ -1,18 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-</head>
-<body>
-<script>
-function addPlugin(aId, aType = "application/x-test") {
-  var embed = document.createElement("embed");
-  embed.setAttribute("id", aId);
-  embed.style.width = "200px";
-  embed.style.height = "200px";
-  embed.setAttribute("type", aType);
-  return document.body.appendChild(embed);
-}
-</script>
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_alternate_content.html b/browser/base/content/test/plugins/xbl/plugin_alternate_content.html
deleted file mode 100644
index f8acc833cc13..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_alternate_content.html
+++ /dev/null
@@ -1,9 +0,0 @@
-<!-- bug 739575 -->
-<html>
-<head><meta http-equiv="content-type" content="text/html; charset=ISO-8859-1">
-</head>
-<body>
-<object id="test" type="application/x-test" style="height: 200px; width:200px">
-<p><a href="about:blank">you should not see this link when plugins are click-to-play</a></p>
-</object>
-</body></html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_big.html b/browser/base/content/test/plugins/xbl/plugin_big.html
deleted file mode 100644
index d11506176c68..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_big.html
+++ /dev/null
@@ -1,9 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-</head>
-<body>
-<embed id="test" style="width: 500px; height: 500px" type="application/x-test">
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_both.html b/browser/base/content/test/plugins/xbl/plugin_both.html
deleted file mode 100644
index 2335366dc0b7..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_both.html
+++ /dev/null
@@ -1,10 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-</head>
-<body>
-<embed id="unknown" style="width: 100px; height: 100px" type="application/x-unknown">
-<embed id="test" style="width: 100px; height: 100px" type="application/x-test">
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_both2.html b/browser/base/content/test/plugins/xbl/plugin_both2.html
deleted file mode 100644
index ba605d6e8c17..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_both2.html
+++ /dev/null
@@ -1,10 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-</head>
-<body>
-<embed id="test" style="width: 100px; height: 100px" type="application/x-test">
-<embed id="unknown" style="width: 100px; height: 100px" type="application/x-unknown">
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_bug744745.html b/browser/base/content/test/plugins/xbl/plugin_bug744745.html
deleted file mode 100644
index d0691c9c0db1..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_bug744745.html
+++ /dev/null
@@ -1,12 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head><meta charset="utf-8"/></head>
-<body>
-<style>
-.x {
-  opacity: 0 !important;
-}
-</style>
-<object id="test" class="x" type="application/x-test" width=200 height=200></object>
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_bug749455.html b/browser/base/content/test/plugins/xbl/plugin_bug749455.html
deleted file mode 100644
index 831dc82f7cef..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_bug749455.html
+++ /dev/null
@@ -1,8 +0,0 @@
-<!-- bug 749455 -->
-<html>
-<head><meta http-equiv="content-type" content="text/html; charset=ISO-8859-1">
-</head>
-<body>
-<embed src="plugin_bug749455.html" type="application/x-test" width="100px" height="100px"></embed>
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_bug787619.html b/browser/base/content/test/plugins/xbl/plugin_bug787619.html
deleted file mode 100644
index cb91116f0452..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_bug787619.html
+++ /dev/null
@@ -1,9 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head><meta charset="utf-8"/></head>
-<body>
-  <a id="wrapper">
-    <embed id="plugin" style="width: 200px; height: 200px" type="application/x-test">
-  </a>
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_bug797677.html b/browser/base/content/test/plugins/xbl/plugin_bug797677.html
deleted file mode 100644
index 1545f36475df..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_bug797677.html
+++ /dev/null
@@ -1,5 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head><meta charset="utf-8"/></head>
-<body><embed id="plugin" type="9000"></embed></body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_bug820497.html b/browser/base/content/test/plugins/xbl/plugin_bug820497.html
deleted file mode 100644
index 4884e9dbe4e0..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_bug820497.html
+++ /dev/null
@@ -1,17 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head><meta charset="utf-8"/></head>
-<body>
-<object id="test" type="application/x-test" width=200 height=200></object>
-<script>
-  function addSecondPlugin() {
-    var object = document.createElement("object");
-    object.type = "application/x-second-test";
-    object.width = 200;
-    object.height = 200;
-    object.id = "secondtest";
-    document.body.appendChild(object);
-  }
-</script>
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_clickToPlayAllow.html b/browser/base/content/test/plugins/xbl/plugin_clickToPlayAllow.html
deleted file mode 100644
index 3f5df19840df..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_clickToPlayAllow.html
+++ /dev/null
@@ -1,9 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-</head>
-<body>
-<embed id="test" style="width: 200px; height: 200px" type="application/x-test">
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_clickToPlayDeny.html b/browser/base/content/test/plugins/xbl/plugin_clickToPlayDeny.html
deleted file mode 100644
index 3f5df19840df..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_clickToPlayDeny.html
+++ /dev/null
@@ -1,9 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-</head>
-<body>
-<embed id="test" style="width: 200px; height: 200px" type="application/x-test">
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_crashCommentAndURL.html b/browser/base/content/test/plugins/xbl/plugin_crashCommentAndURL.html
deleted file mode 100644
index d6bba4173277..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_crashCommentAndURL.html
+++ /dev/null
@@ -1,26 +0,0 @@
-<!DOCTYPE html>
-<html>
-  <head>
-    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
-    <script type="text/javascript">
-      function crash() {
-        var plugin = document.getElementById("plugin");
-        var argStr = decodeURIComponent(window.location.search.substr(1));
-        if (argStr) {
-          var args = JSON.parse(argStr);
-          for (var key in args)
-            plugin.setAttribute(key, args[key]);
-        }
-        try {
-          plugin.crash();
-        } catch (err) {}
-      }
-    </script>
-  </head>
-  <body onload="crash();">
-    <embed id="plugin" type="application/x-test"
-           width="400" height="400"
-           drawmode="solid" color="FF00FFFF">
-    </embed>
-  </body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_favorfallback.html b/browser/base/content/test/plugins/xbl/plugin_favorfallback.html
deleted file mode 100644
index 6eaf15499446..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_favorfallback.html
+++ /dev/null
@@ -1,96 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head><meta charset="utf-8"/></head>
-<body>
-<style>
-.testcase {
-    display: none;
-}
-object {
-    width: 200px;
-    height: 200px;
-}
-</style>
-
-<!-- Tests that a <video> tag in the fallback content favors the fallback content -->
-<div id="testcase_video" class="testcase">
-    <object class="expected_ctp" type="application/x-shockwave-flash-test">
-        Unexpected fallback
-    </object>
-    <object class="expected_fallback" type="application/x-shockwave-flash-test">
-        <video></video>
-        Expected fallback
-    </object>
-</div>
-
-<!-- Tests that an object with no src specified (no data="") favors the fallback content -->
-<div id="testcase_nosrc" class="testcase">
-    <!-- We must use an existing and valid file here because otherwise the failed load
-         triggers the plugin's alternate content, indepedent of the favor-fallback code path -->
-    <object class="expected_ctp" type="application/x-shockwave-flash-test" data="plugin_simple_blank.swf">
-        Unexpected fallback
-    </object>
-    <object class="expected_fallback" type="application/x-shockwave-flash-test">
-        Expected fallback
-    </object>
-</div>
-
-<!-- Tests that an <embed> tag in the fallback content forces the plugin content,
-     when fallback is defaulting to true -->
-<div id="testcase_embed" class="testcase">
-    <object class="expected_ctp" type="application/x-shockwave-flash-test">
-        <embed></embed>
-        Unexpected fallback
-    </object>
-    <object class="expected_fallback" type="application/x-shockwave-flash-test">
-        Expected fallback
-    </object>
-</div>
-
-<!-- Tests that links to adobe.com inside the fallback content forces the plugin content,
-     when fallback is defaulting to true -->
-<div id="testcase_adobelink" class="testcase">
-    <object class="expected_ctp" type="application/x-shockwave-flash-test">
-        <a href="https://www.adobe.com">Go to adobe.com</a>
-        Unexpected fallback
-    </object>
-    <object class="expected_ctp" type="application/x-shockwave-flash-test">
-        <a href="https://adobe.com">Go to adobe.com</a>
-        Unexpected fallback
-    </object>
-    <object class="expected_fallback" type="application/x-shockwave-flash-test">
-        Expected fallback
-    </object>
-</div>
-
-<!-- Tests that instructions to download or install flash inside the fallback content
-     forces the plugin content, when fallback is defaulting to true -->
-<div id="testcase_installinstructions" class="testcase">
-    <object class="expected_ctp" type="application/x-shockwave-flash-test">
-        Install -- Unexpected fallback
-    </object>
-    <object class="expected_ctp" type="application/x-shockwave-flash-test">
-        Flash -- Unexpected fallback
-    </object>
-    <object class="expected_ctp" type="application/x-shockwave-flash-test">
-        Download -- Unexpected fallback
-    </object>
-    <object class="expected_fallback" type="application/x-shockwave-flash-test">
-        <!-- Tests that the words Install, Flash or Download do not trigger
-             this behavior if it's just inside a comment, and not part of
-             the text content -->
-        Expected Fallback
-    </object>
-    <object class="expected_fallback" type="application/x-shockwave-flash-test">
-        Expected fallback
-    </object>
-</div>
-
-<script>
-    let queryString = location.search;
-    let match = /^\?testcase=([a-z]+)$/.exec(queryString);
-    let testcase = match[1];
-    document.getElementById(`testcase_${testcase}`).style.display = "block";
-</script>
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_hidden_to_visible.html b/browser/base/content/test/plugins/xbl/plugin_hidden_to_visible.html
deleted file mode 100644
index eeacc1874775..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_hidden_to_visible.html
+++ /dev/null
@@ -1,11 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-</head>
-<body>
-  <div id="container" style="display: none">
-    <object id="test" type="application/x-test" style="width: 200px; height: 200px;"></object>
-  </div>
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_iframe.html b/browser/base/content/test/plugins/xbl/plugin_iframe.html
deleted file mode 100644
index 239c9a7719ea..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_iframe.html
+++ /dev/null
@@ -1,9 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-</head>
-<body>
-<iframe id="frame" with="400" height="400" src="plugin_test.html">
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_outsideScrollArea.html b/browser/base/content/test/plugins/xbl/plugin_outsideScrollArea.html
deleted file mode 100644
index c6ef50d5db1c..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_outsideScrollArea.html
+++ /dev/null
@@ -1,25 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-<style type="text/css">
-#container {
-  position: fixed;
-  top: 0;
-  bottom: 0;
-  width: 100%;
-  height: 100%;
-  background: blue;
-}
-
-#test {
-  width: 400px;
-  height: 400px;
-  position: absolute;
-}
-</style>
-</head>
-<body>
-  <div id="container"></div>
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_overlay_styles.html b/browser/base/content/test/plugins/xbl/plugin_overlay_styles.html
deleted file mode 100644
index 500045d16e4c..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_overlay_styles.html
+++ /dev/null
@@ -1,29 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-</head>
-<body>
-
-  <div id="testcase1" class="testcase">
-    <object width="10" height="10" type="application/x-test"></object>
-  </div>
-
-  <div id="testcase2" class="testcase">
-    <object width="40" height="40" type="application/x-test"></object>
-  </div>
-
-  <div id="testcase3" class="testcase">
-    <object width="100" height="70" type="application/x-test"></object>
-  </div>
-
-  <div id="testcase4" class="testcase">
-    <object width="200" height="200" type="application/x-test"></object>
-  </div>
-
-  <div id="testcase5" class="testcase">
-    <object width="300" height="300" type="application/x-test"></object>
-  </div>
-
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_shouldShowOverlay.html b/browser/base/content/test/plugins/xbl/plugin_shouldShowOverlay.html
deleted file mode 100644
index 24d07d164260..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_shouldShowOverlay.html
+++ /dev/null
@@ -1,116 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-<style>
-object {
-  width: 200px;
-  height: 200px;
-}
-
-.testcase {
-  position: relative;
-  margin-bottom: 5px;
-}
-
-.cover {
-  position: absolute;
-  width: 20px;
-  height: 20px;
-  background-color: green;
-}
-</style>
-</head>
-<body>
-
-  <div id="testcase1" class="testcase" shouldshow="true"
-       style="top: -100px">
-    <!-- Should show overlay even though the top part is outside
-       of the page. -->
-    <object type="application/x-test"></object>
-  </div>
-
-  <div id="testcase2" class="testcase" shouldshow="true"
-       style="left: -100px">
-    <!-- Should show overlay even though the left part is outside
-       of the page. -->
-    <object type="application/x-test"></object>
-  </div>
-
-  <div id="testcase3" class="testcase" shouldshow="false"
-       style="left: -210px">
-    <!-- The object is entirely outside of the page, so the overlay
-         should NOT show. -->
-    <object type="application/x-test"></object>
-  </div>
-
-  <div id="testcase4" class="testcase" shouldshow="true">
-    <!-- Should show overlay even though the top-left corner is covered. -->
-    <div class="cover" style="top: 0; left: 0"></div>
-    <object type="application/x-test"></object>
-  </div>
-
-  <div id="testcase5" class="testcase" shouldshow="true">
-    <!-- Should show overlay even though the top-right corner is covered. -->
-    <div class="cover" style="top: 0; left: 180px"></div>
-    <object type="application/x-test"></object>
-  </div>
-
-  <div id="testcase6" class="testcase" shouldshow="true">
-    <!-- Should show overlay even though the bottom-left corner is covered. -->
-    <div class="cover" style="top: 180px; left: 0"></div>
-    <object type="application/x-test"></object>
-  </div>
-
-
-  <div id="testcase7" class="testcase" shouldshow="true">
-    <!-- Should show overlay even though the bottom-right corner is covered. -->
-    <div class="cover" style="top: 180px; left: 180px"></div>
-    <object type="application/x-test"></object>
-  </div>
-
-  <div id="testcase8" class="testcase" shouldshow="true">
-    <!-- Should show overlay even though the center is covered. -->
-    <div class="cover" style="top: 90px; left: 90px"></div>
-    <object type="application/x-test"></object>
-  </div>
-
-  <div id="testcase9" class="testcase" shouldshow="true">
-    <!-- Should show overlay even though multiple points are covered,
-       but not all of them. -->
-    <div class="cover" style="top: 0; left: 0"></div>
-    <div class="cover" style="top: 0; left: 180px"></div>
-    <div class="cover" style="top: 180px; left: 0"></div>
-    <div class="cover" style="top: 180px; left: 180px"></div>
-    <object type="application/x-test"></object>
-  </div>
-
-  <div id="testcase10" class="testcase" shouldshow="true">
-    <!-- Another case where 4 are covered, but not all. -->
-    <div class="cover" style="top: 90px; left: 90px"></div>
-    <div class="cover" style="top: 0; left: 180px"></div>
-    <div class="cover" style="top: 180px; left: 0"></div>
-    <div class="cover" style="top: 180px; left: 180px"></div>
-    <object type="application/x-test"></object>
-  </div>
-
-  <div id="testcase11" class="testcase" shouldshow="false">
-    <!-- All corners and center are covered here, so in this
-         case the overlay should NOT show. -->
-    <div class="cover" style="top: 0; left: 0"></div>
-    <div class="cover" style="top: 0; left: 180px"></div>
-    <div class="cover" style="top: 180px; left: 0"></div>
-    <div class="cover" style="top: 180px; left: 180px"></div>
-    <div class="cover" style="top: 90px; left: 90px"></div>
-    <object type="application/x-test"></object>
-  </div>
-
-  <div id="testcase12" class="testcase" shouldshow="false">
-        <!-- All corners and center are covered here, by a single
-        element. In this case the overlay should NOT show. -->
-    <div class="cover" style="width: 200px; height:200px"></div>
-    <object type="application/x-test"></object>
-  </div>
-
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_simple_blank.swf b/browser/base/content/test/plugins/xbl/plugin_simple_blank.swf
deleted file mode 100644
index b846387eb8b8..000000000000
Binary files a/browser/base/content/test/plugins/xbl/plugin_simple_blank.swf and /dev/null differ
diff --git a/browser/base/content/test/plugins/xbl/plugin_small.html b/browser/base/content/test/plugins/xbl/plugin_small.html
deleted file mode 100644
index f37ee28c7b2f..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_small.html
+++ /dev/null
@@ -1,9 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-</head>
-<body>
-<embed id="test" style="width: 10px; height: 10px" type="application/x-test">
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_small_2.html b/browser/base/content/test/plugins/xbl/plugin_small_2.html
deleted file mode 100644
index ebc5ffe848e4..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_small_2.html
+++ /dev/null
@@ -1,9 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-</head>
-<body>
-<embed id="test" style="width: 10px; height: 10px" type="application/x-second-test">
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_syncRemoved.html b/browser/base/content/test/plugins/xbl/plugin_syncRemoved.html
deleted file mode 100644
index b54798c36c79..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_syncRemoved.html
+++ /dev/null
@@ -1,15 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-<body>
-<script type="text/javascript">
-  // create an embed, insert it in the doc and immediately remove it
-  var embed = document.createElement("embed");
-  embed.setAttribute("id", "test");
-  embed.setAttribute("type", "application/x-test");
-  embed.setAttribute("style", "width: 0px; height: 0px;");
-  document.body.appendChild(embed);
-  window.getComputedStyle(embed).top;
-  document.body.remove(embed);
-</script>
diff --git a/browser/base/content/test/plugins/xbl/plugin_test.html b/browser/base/content/test/plugins/xbl/plugin_test.html
deleted file mode 100644
index 3d4f43e6a5c6..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_test.html
+++ /dev/null
@@ -1,9 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-</head>
-<body>
-<embed id="test" style="width: 300px; height: 300px" type="application/x-test">
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_test2.html b/browser/base/content/test/plugins/xbl/plugin_test2.html
deleted file mode 100644
index 95614c930c70..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_test2.html
+++ /dev/null
@@ -1,10 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-</head>
-<body>
-<embed id="test1" style="width: 200px; height: 200px" type="application/x-test">
-<embed id="test2" style="width: 200px; height: 200px" type="application/x-test">
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_test3.html b/browser/base/content/test/plugins/xbl/plugin_test3.html
deleted file mode 100644
index 215c02326438..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_test3.html
+++ /dev/null
@@ -1,9 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-</head>
-<body>
-<embed id="test" style="width: 0px; height: 0px" type="application/x-test">
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_two_types.html b/browser/base/content/test/plugins/xbl/plugin_two_types.html
deleted file mode 100644
index 2359d2ec10fa..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_two_types.html
+++ /dev/null
@@ -1,9 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head><meta charset="utf-8"/></head>
-<body>
-<embed id="test" style="width: 200px; height: 200px" type="application/x-test"/>
-<embed id="secondtestA" style="width: 200px; height: 200px" type="application/x-second-test"/>
-<embed id="secondtestB" style="width: 200px; height: 200px" type="application/x-second-test"/>
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_unknown.html b/browser/base/content/test/plugins/xbl/plugin_unknown.html
deleted file mode 100644
index 578f455cc259..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_unknown.html
+++ /dev/null
@@ -1,9 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-</head>
-<body>
-<embed id="unknown" style="width: 100px; height: 100px" type="application/x-unknown">
-</body>
-</html>
diff --git a/browser/base/content/test/plugins/xbl/plugin_zoom.html b/browser/base/content/test/plugins/xbl/plugin_zoom.html
deleted file mode 100644
index f9e5986581f4..000000000000
--- a/browser/base/content/test/plugins/xbl/plugin_zoom.html
+++ /dev/null
@@ -1,10 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-</head>
-<body>
-<!-- The odd width and height are here to trigger bug 972237. -->
-<embed id="test" style="width: 99.789%; height: 99.123%" type="application/x-test">
-</body>
-</html>
diff --git a/browser/base/moz.build b/browser/base/moz.build
index a058a9341108..36d1849962ee 100644
--- a/browser/base/moz.build
+++ b/browser/base/moz.build
@@ -37,7 +37,6 @@ BROWSER_CHROME_MANIFESTS += [
     'content/test/performance/lowdpi/browser.ini',
     'content/test/permissions/browser.ini',
     'content/test/plugins/browser.ini',
-    'content/test/plugins/xbl/browser.ini',
     'content/test/popupNotifications/browser.ini',
     'content/test/popups/browser.ini',
     'content/test/referrer/browser.ini',
diff --git a/browser/themes/linux/preferences/applications.css b/browser/themes/linux/preferences/applications.css
index fd4d001e09bc..67af4ab0ee0c 100644
--- a/browser/themes/linux/preferences/applications.css
+++ b/browser/themes/linux/preferences/applications.css
@@ -42,7 +42,7 @@ menuitem[appHandlerIcon="save"] {
 
 richlistitem[appHandlerIcon="plugin"],
 menuitem[appHandlerIcon="plugin"] {
-  list-style-image: url("chrome://global/skin/plugins/pluginGeneric.svg");
+  list-style-image: url("chrome://mozapps/skin/plugins/pluginGeneric.svg");
 }
 
 .actionsMenu .menulist-icon {
diff --git a/browser/themes/osx/preferences/applications.css b/browser/themes/osx/preferences/applications.css
index 8a4ac6e46762..41a2ee1f8354 100644
--- a/browser/themes/osx/preferences/applications.css
+++ b/browser/themes/osx/preferences/applications.css
@@ -53,7 +53,7 @@ menuitem[appHandlerIcon="save"] {
 
 richlistitem[appHandlerIcon="plugin"],
 menuitem[appHandlerIcon="plugin"] {
-  list-style-image: url("chrome://global/skin/plugins/pluginGeneric.svg");
+  list-style-image: url("chrome://mozapps/skin/plugins/pluginGeneric.svg");
 }
 
 /* Repeat what menu.css does for .menuitem-iconic */
diff --git a/browser/themes/shared/notification-icons.inc.css b/browser/themes/shared/notification-icons.inc.css
index 8fd1dd9435f9..344cbb471107 100644
--- a/browser/themes/shared/notification-icons.inc.css
+++ b/browser/themes/shared/notification-icons.inc.css
@@ -253,12 +253,12 @@ html|*#webRTC-previewVideo {
 /* PLUGINS */
 
 .plugin-icon {
-  list-style-image: url(chrome://global/skin/plugins/plugin.svg);
+  list-style-image: url(chrome://mozapps/skin/plugins/plugin.svg);
   transition: fill 1.5s;
 }
 
 .plugin-icon.blocked-permission-icon {
-  list-style-image: url(chrome://global/skin/plugins/plugin-blocked.svg);
+  list-style-image: url(chrome://mozapps/skin/plugins/plugin-blocked.svg);
 }
 
 #plugin-icon-badge {
@@ -289,7 +289,7 @@ html|*#webRTC-previewVideo {
 }
 
 .plugin-blocked > .plugin-icon {
-  list-style-image: url(chrome://global/skin/plugins/plugin-blocked.svg);
+  list-style-image: url(chrome://mozapps/skin/plugins/plugin-blocked.svg);
   fill: #d92215 !important;
 }
 
diff --git a/browser/themes/windows/preferences/applications.css b/browser/themes/windows/preferences/applications.css
index 5315fcdca20d..08680189af0b 100644
--- a/browser/themes/windows/preferences/applications.css
+++ b/browser/themes/windows/preferences/applications.css
@@ -42,7 +42,7 @@ menuitem[appHandlerIcon="save"] {
 
 richlistitem[appHandlerIcon="plugin"],
 menuitem[appHandlerIcon="plugin"] {
-  list-style-image: url("chrome://global/skin/plugins/pluginGeneric.svg");
+  list-style-image: url("chrome://mozapps/skin/plugins/pluginGeneric.svg");
 }
 
 .actionsMenu .menulist-icon {
diff --git a/caps/tests/mochitest/test_bug292789.html b/caps/tests/mochitest/test_bug292789.html
index 406fd81423d0..e07fc4ce3c0d 100644
--- a/caps/tests/mochitest/test_bug292789.html
+++ b/caps/tests/mochitest/test_bug292789.html
@@ -60,8 +60,8 @@ function testScriptSrc(aCallback) {
 
 /** <img src=""> tests **/
 var img_global = "chrome://global/skin/media/error.png";
-var img_mozapps = "chrome://mozapps/skin/extensions/extensionGeneric.svg";
-var res_mozapps = "resource://gre/chrome/toolkit/skin/classic/mozapps/extensions/extensionGeneric.svg";
+var img_mozapps = "chrome://mozapps/skin/plugins/contentPluginCrashed.png";
+var res_mozapps = "resource://gre/chrome/toolkit/skin/classic/mozapps/plugins/contentPluginCrashed.png";
 
 var imgTests = [[img_global, "success"],
                 [img_mozapps, "fail"],
diff --git a/dom/base/nsObjectLoadingContent.cpp b/dom/base/nsObjectLoadingContent.cpp
index 7fb41b800069..6b4a40514271 100644
--- a/dom/base/nsObjectLoadingContent.cpp
+++ b/dom/base/nsObjectLoadingContent.cpp
@@ -605,7 +605,6 @@ nsObjectLoadingContent::BindToTree(nsIDocument* aDocument,
   if (aDocument) {
     aDocument->AddPlugin(this);
   }
-
   return NS_OK;
 }
 
@@ -635,21 +634,6 @@ nsObjectLoadingContent::UnbindFromTree(bool aDeep, bool aNullParent)
     ///             would keep the docshell around, but trash the frameloader
     UnloadObject();
   }
-
-  // Unattach plugin problem UIWidget if any.
-  if (thisElement->IsInComposedDoc() && thisElement->GetShadowRoot()) {
-    nsContentUtils::AddScriptRunner(NS_NewRunnableFunction(
-      "nsObjectLoadingContent::UnbindFromTree::UAWidgetUnbindFromTree",
-      [thisElement]() {
-        nsContentUtils::DispatchChromeEvent(
-          thisElement->OwnerDoc(), thisElement,
-          NS_LITERAL_STRING("UAWidgetUnbindFromTree"),
-          CanBubble::eYes, Cancelable::eNo);
-        thisElement->UnattachShadow();
-      })
-    );
-  }
-
   if (mType == eType_Plugin) {
     nsIDocument* doc = thisElement->GetComposedDoc();
     if (doc && doc->IsActive()) {
@@ -2648,23 +2632,25 @@ nsObjectLoadingContent::NotifyStateChanged(ObjectType aOldType,
        " (sync %i, notify %i)", this, aOldType, aOldState.GetInternalValue(),
        mType, ObjectState().GetInternalValue(), aSync, aNotify));
 
-  nsCOMPtr<dom::Element> thisEl =
+  nsCOMPtr<nsIContent> thisContent =
     do_QueryInterface(static_cast<nsIImageLoadingContent*>(this));
-  MOZ_ASSERT(thisEl, "must be an element");
+  NS_ASSERTION(thisContent, "must be a content");
+
+  NS_ASSERTION(thisContent->IsElement(), "Not an element?");
 
   // XXX(johns): A good bit of the code below replicates UpdateState(true)
 
   // Unfortunately, we do some state changes without notifying
   // (e.g. in Fallback when canceling image requests), so we have to
   // manually notify object state changes.
-  thisEl->UpdateState(false);
+  thisContent->AsElement()->UpdateState(false);
 
   if (!aNotify) {
     // We're done here
     return;
   }
 
-  nsIDocument* doc = thisEl->GetComposedDoc();
+  nsIDocument* doc = thisContent->GetComposedDoc();
   if (!doc) {
     return; // Nothing to do
   }
@@ -2676,59 +2662,24 @@ nsObjectLoadingContent::NotifyStateChanged(ObjectType aOldType,
   }
 
   if (newState != aOldState) {
-    MOZ_ASSERT(thisEl->IsInComposedDoc(), "Something is confused");
+    NS_ASSERTION(thisContent->IsInComposedDoc(), "Something is confused");
     // This will trigger frame construction
     EventStates changedBits = aOldState ^ newState;
     {
       nsAutoScriptBlocker scriptBlocker;
-      doc->ContentStateChanged(thisEl, changedBits);
-    }
-
-    // Create/destroy plugin problem UAWidget if needed.
-    if (nsContentUtils::IsUAWidgetEnabled()) {
-      const EventStates pluginProblemState =
-        NS_EVENT_STATE_HANDLER_BLOCKED |
-        NS_EVENT_STATE_HANDLER_CRASHED |
-        NS_EVENT_STATE_TYPE_CLICK_TO_PLAY |
-        NS_EVENT_STATE_VULNERABLE_UPDATABLE |
-        NS_EVENT_STATE_VULNERABLE_NO_UPDATE;
-
-      bool hadProblemState = !(aOldState & pluginProblemState).IsEmpty();
-      bool hasProblemState = !(newState & pluginProblemState).IsEmpty();
-
-      if (hadProblemState && !hasProblemState) {
-        nsContentUtils::AddScriptRunner(NS_NewRunnableFunction(
-          "nsObjectLoadingContent::UnbindFromTree::UAWidgetUnbindFromTree",
-          [thisEl]() {
-            nsContentUtils::DispatchChromeEvent(
-              thisEl->OwnerDoc(), thisEl,
-              NS_LITERAL_STRING("UAWidgetUnbindFromTree"),
-              CanBubble::eYes, Cancelable::eNo);
-            thisEl->UnattachShadow();
-          })
-        );
-      } else if (!hadProblemState && hasProblemState) {
-        nsGenericHTMLElement::FromNode(thisEl)->AttachAndSetUAShadowRoot();
-
-        AsyncEventDispatcher* dispatcher =
-          new AsyncEventDispatcher(thisEl,
-                                   NS_LITERAL_STRING("UAWidgetBindToTree"),
-                                   CanBubble::eYes,
-                                   ChromeOnlyDispatch::eYes);
-        dispatcher->RunDOMEventWhenSafe();
-      }
+      doc->ContentStateChanged(thisContent, changedBits);
     }
   } else if (aOldType != mType) {
     // If our state changed, then we already recreated frames
     // Otherwise, need to do that here
     nsCOMPtr<nsIPresShell> shell = doc->GetShell();
     if (shell) {
-      shell->PostRecreateFramesFor(thisEl);
+      shell->PostRecreateFramesFor(thisContent->AsElement());
     }
   }
 
   if (aSync) {
-    MOZ_ASSERT(InActiveDocument(thisEl), "Something is confused");
+    NS_ASSERTION(InActiveDocument(thisContent), "Something is confused");
     // Make sure that frames are actually constructed immediately.
     doc->FlushPendingNotifications(FlushType::Frames);
   }
diff --git a/dom/plugins/test/mochitest/test_crash_submit.xul b/dom/plugins/test/mochitest/test_crash_submit.xul
index f76941e0a326..0ebd7b8bcad7 100644
--- a/dom/plugins/test/mochitest/test_crash_submit.xul
+++ b/dom/plugins/test/mochitest/test_crash_submit.xul
@@ -117,8 +117,7 @@ function onPluginCrashed(aEvent) {
 
   let submitButton = document.getAnonymousElementByAttribute(aEvent.target,
                                                              "class",
-                                                             "submitButton") ||
-                     aEvent.target.openOrClosedShadowRoot.getElementById("submitButton");
+                                                             "submitButton");
   // try to submit this report
   sendMouseEvent({type:'click'}, submitButton, window);
 }
diff --git a/dom/plugins/test/mochitest/test_hang_submit.xul b/dom/plugins/test/mochitest/test_hang_submit.xul
index ef380316b995..63a284f63077 100644
--- a/dom/plugins/test/mochitest/test_hang_submit.xul
+++ b/dom/plugins/test/mochitest/test_hang_submit.xul
@@ -121,8 +121,7 @@ function onPluginCrashed(aEvent) {
 
   let submitButton = document.getAnonymousElementByAttribute(aEvent.target,
                                                              "class",
-                                                             "submitButton") ||
-                     aEvent.target.openOrClosedShadowRoot.getElementById("submitButton");
+                                                             "submitButton");
   // try to submit this report
   sendMouseEvent({type:'click'}, submitButton, window);
 }
diff --git a/mobile/android/chrome/content/PluginHelper.js b/mobile/android/chrome/content/PluginHelper.js
new file mode 100644
index 000000000000..934c8784a5b1
--- /dev/null
+++ b/mobile/android/chrome/content/PluginHelper.js
@@ -0,0 +1,226 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+XPCOMUtils.defineLazyGetter(this, "GlobalEventDispatcher", () => EventDispatcher.instance);
+
+var PluginHelper = {
+  showDoorHanger: function(aTab) {
+    if (!aTab.browser)
+      return;
+
+    // Even though we may not end up showing a doorhanger, this flag
+    // lets us know that we've tried to show a doorhanger.
+    aTab.shouldShowPluginDoorhanger = false;
+
+    let uri = aTab.browser.currentURI;
+
+    // If the user has previously set a plugins permission for this website,
+    // either play or don't play the plugins instead of showing a doorhanger.
+    let permValue = Services.perms.testPermission(uri, "plugins");
+    if (permValue != Services.perms.UNKNOWN_ACTION) {
+      if (permValue == Services.perms.ALLOW_ACTION)
+        PluginHelper.playAllPlugins(aTab.browser.contentWindow);
+
+      return;
+    }
+
+    let message = Strings.browser.formatStringFromName("clickToPlayPlugins.message2",
+                                                       [uri.host], 1);
+    let buttons = [
+      {
+        label: Strings.browser.GetStringFromName("clickToPlayPlugins.dontActivate"),
+        callback: function(aChecked) {
+          // If the user checked "Don't ask again", make a permanent exception
+          if (aChecked)
+            Services.perms.add(uri, "plugins", Ci.nsIPermissionManager.DENY_ACTION);
+
+          // Other than that, do nothing
+        },
+      },
+      {
+        label: Strings.browser.GetStringFromName("clickToPlayPlugins.activate"),
+        callback: function(aChecked) {
+          // If the user checked "Don't ask again", make a permanent exception
+          if (aChecked)
+            Services.perms.add(uri, "plugins", Ci.nsIPermissionManager.ALLOW_ACTION);
+
+          PluginHelper.playAllPlugins(aTab.browser.contentWindow);
+        },
+        positive: true,
+      },
+    ];
+
+    // Add a checkbox with a "Don't ask again" message if the uri contains a
+    // host. Adding a permanent exception will fail if host is not present.
+    let options = uri.host ? { checkbox: Strings.browser.GetStringFromName("clickToPlayPlugins.dontAskAgain") } : {};
+
+    NativeWindow.doorhanger.show(message, "ask-to-play-plugins", buttons, aTab.id, options);
+  },
+
+  delayAndShowDoorHanger: function(aTab) {
+    // To avoid showing the doorhanger if there are also visible plugin
+    // overlays on the page, delay showing the doorhanger to check if
+    // visible plugins get added in the near future.
+    if (!aTab.pluginDoorhangerTimeout) {
+      aTab.pluginDoorhangerTimeout = setTimeout(function() {
+        if (this.shouldShowPluginDoorhanger) {
+          PluginHelper.showDoorHanger(this);
+        }
+      }.bind(aTab), 500);
+    }
+  },
+
+  playAllPlugins: function(aContentWindow) {
+    let cwu = aContentWindow.windowUtils;
+    // XXX not sure if we should enable plugins for the parent documents...
+    let plugins = cwu.plugins;
+    if (!plugins || !plugins.length)
+      return;
+
+    plugins.forEach(this.playPlugin);
+  },
+
+  playPlugin: function(plugin) {
+    let objLoadingContent = plugin.QueryInterface(Ci.nsIObjectLoadingContent);
+    let mimeType = objLoadingContent.actualType;
+    if (mimeType) {
+      GlobalEventDispatcher.sendRequest({ type: "PluginHelper:playFlash" });
+    }
+    if (!objLoadingContent.activated)
+      objLoadingContent.playPlugin();
+  },
+
+  getPluginPreference: function getPluginPreference() {
+    let pluginDisable = Services.prefs.getBoolPref("plugin.disable");
+    if (pluginDisable)
+      return "0";
+
+    let state = Services.prefs.getIntPref("plugin.default.state");
+    return state == Ci.nsIPluginTag.STATE_CLICKTOPLAY ? "2" : "1";
+  },
+
+  setPluginPreference: function setPluginPreference(aValue) {
+    switch (aValue) {
+      case "0": // Enable Plugins = No
+        Services.prefs.setBoolPref("plugin.disable", true);
+        Services.prefs.clearUserPref("plugin.default.state");
+        break;
+      case "1": // Enable Plugins = Yes
+        Services.prefs.clearUserPref("plugin.disable");
+        Services.prefs.setIntPref("plugin.default.state", Ci.nsIPluginTag.STATE_ENABLED);
+        break;
+      case "2": // Enable Plugins = Tap to Play (default)
+        Services.prefs.clearUserPref("plugin.disable");
+        Services.prefs.clearUserPref("plugin.default.state");
+        break;
+    }
+  },
+
+  // Copied from /browser/base/content/browser.js
+  isTooSmall: function(plugin, overlay) {
+    // Is the <object>'s size too small to hold what we want to show?
+    let pluginRect = plugin.getBoundingClientRect();
+    // XXX bug 446693. The text-shadow on the submitted-report text at
+    //     the bottom causes scrollHeight to be larger than it should be.
+    let overflows = (overlay.scrollWidth > pluginRect.width) ||
+                    (overlay.scrollHeight - 5 > pluginRect.height);
+
+    return overflows;
+  },
+
+  getPluginMimeType: function(plugin) {
+    var tagMimetype = plugin.actualType;
+
+    if (tagMimetype == "") {
+      tagMimetype = plugin.type;
+    }
+
+    return tagMimetype;
+  },
+
+  handlePluginBindingAttached: function(aTab, aEvent) {
+    let plugin = aEvent.target;
+    let doc = plugin.ownerDocument;
+    let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
+    if (!overlay || overlay._bindingHandled) {
+      return;
+    }
+    overlay._bindingHandled = true;
+
+    let eventType = PluginHelper._getBindingType(plugin);
+    if (!eventType) {
+      // Not all bindings have handlers
+      return;
+    }
+
+    switch (eventType) {
+      case "PluginClickToPlay": {
+        // Check if plugins have already been activated for this page, or if
+        // the user has set a permission to always play plugins on the site
+        if (aTab.clickToPlayPluginsActivated ||
+            Services.perms.testPermission(aTab.browser.currentURI, "plugins") ==
+            Services.perms.ALLOW_ACTION) {
+          PluginHelper.playPlugin(plugin);
+          return;
+        }
+
+        // If the plugin is hidden, or if the overlay is too small, show a
+        // doorhanger notification
+        if (PluginHelper.isTooSmall(plugin, overlay)) {
+          PluginHelper.delayAndShowDoorHanger(aTab);
+        } else {
+          // There's a large enough visible overlay that we don't need to show
+          // the doorhanger.
+          aTab.shouldShowPluginDoorhanger = false;
+          overlay.classList.add("visible");
+        }
+
+        // Add click to play listener to the overlay
+        overlay.addEventListener("click", function(e) {
+          if (!e.isTrusted)
+            return;
+          e.preventDefault();
+          let win = e.target.ownerGlobal.top;
+          let tab = BrowserApp.getTabForWindow(win);
+          tab.clickToPlayPluginsActivated = true;
+          PluginHelper.playAllPlugins(win);
+
+          NativeWindow.doorhanger.hide("ask-to-play-plugins", tab.id);
+        }, true);
+
+        // Add handlers for over- and underflow in case the plugin gets resized
+        plugin.addEventListener("overflow", function(event) {
+          overlay.classList.remove("visible");
+          PluginHelper.delayAndShowDoorHanger(aTab);
+        });
+        plugin.addEventListener("underflow", function(event) {
+          // This is also triggered if only one dimension underflows,
+          // the other dimension might still overflow
+          if (!PluginHelper.isTooSmall(plugin, overlay)) {
+            overlay.classList.add("visible");
+          }
+        });
+
+        break;
+      }
+    }
+  },
+
+  // Helper to get the binding handler type from a plugin object
+  _getBindingType: function(plugin) {
+    if (!(plugin instanceof Ci.nsIObjectLoadingContent))
+      return null;
+
+    switch (plugin.pluginFallbackType) {
+      case Ci.nsIObjectLoadingContent.PLUGIN_UNSUPPORTED:
+        return "PluginNotFound";
+      case Ci.nsIObjectLoadingContent.PLUGIN_CLICK_TO_PLAY:
+        return "PluginClickToPlay";
+      default:
+        // Not all states map to a handler
+        return null;
+    }
+  },
+};
diff --git a/mobile/android/chrome/jar.mn b/mobile/android/chrome/jar.mn
index dda0e979ec23..491660966b64 100644
--- a/mobile/android/chrome/jar.mn
+++ b/mobile/android/chrome/jar.mn
@@ -30,6 +30,7 @@ chrome.jar:
   content/EmbedRT.js                   (content/EmbedRT.js)
   content/MemoryObserver.js            (content/MemoryObserver.js)
   content/ConsoleAPI.js                (content/ConsoleAPI.js)
+  content/PluginHelper.js              (content/PluginHelper.js)
   content/PrintHelper.js               (content/PrintHelper.js)
   content/OfflineApps.js               (content/OfflineApps.js)
   content/MasterPassword.js            (content/MasterPassword.js)
diff --git a/toolkit/actors/UAWidgetsChild.jsm b/toolkit/actors/UAWidgetsChild.jsm
index 09a4f49e4575..6a9521bcf35b 100644
--- a/toolkit/actors/UAWidgetsChild.jsm
+++ b/toolkit/actors/UAWidgetsChild.jsm
@@ -56,10 +56,10 @@ class UAWidgetsChild extends ActorChild {
         uri = "chrome://global/content/elements/datetimebox.js";
         widgetName = "DateTimeBoxWidget";
         break;
+      case "applet":
       case "embed":
       case "object":
-        uri = "chrome://global/content/elements/pluginProblem.js";
-        widgetName = "PluginProblemWidget";
+        // TODO (pluginProblems)
         break;
       case "marquee":
         uri = "chrome://global/content/elements/marquee.js";
diff --git a/toolkit/content/jar.mn b/toolkit/content/jar.mn
index 1553449ed960..ea78f437ea2a 100644
--- a/toolkit/content/jar.mn
+++ b/toolkit/content/jar.mn
@@ -97,7 +97,6 @@ toolkit.jar:
    content/global/elements/editor.js          (widgets/editor.js)
    content/global/elements/general.js          (widgets/general.js)
    content/global/elements/notificationbox.js  (widgets/notificationbox.js)
-   content/global/elements/pluginProblem.js    (widgets/pluginProblem.js)
    content/global/elements/radio.js            (widgets/radio.js)
    content/global/elements/marquee.css         (widgets/marquee.css)
    content/global/elements/marquee.js          (widgets/marquee.js)
diff --git a/toolkit/content/widgets/pluginProblem.js b/toolkit/content/widgets/pluginProblem.js
deleted file mode 100644
index ef19915fc01d..000000000000
--- a/toolkit/content/widgets/pluginProblem.js
+++ /dev/null
@@ -1,79 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
-  * License, v. 2.0. If a copy of the MPL was not distributed with this
-  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-"use strict";
-
-// This is a UA Widget. It runs in per-origin UA widget scope,
-// to be loaded by UAWidgetsChild.jsm.
-
-this.PluginProblemWidget = class {
-  constructor(shadowRoot) {
-    this.shadowRoot = shadowRoot;
-    this.element = shadowRoot.host;
-    this.window = this.element.ownerGlobal;
-
-    const parser = new this.window.DOMParser();
-    let parserDoc = parser.parseFromString(`
-      <!DOCTYPE bindings [
-        <!ENTITY % pluginproblemDTD SYSTEM "chrome://pluginproblem/locale/pluginproblem.dtd">
-        <!ENTITY % globalDTD SYSTEM "chrome://global/locale/global.dtd">
-        <!ENTITY % brandDTD SYSTEM "chrome://branding/locale/brand.dtd" >
-        %pluginproblemDTD;
-        %globalDTD;
-        %brandDTD;
-      ]>
-      <div xmlns="http://www.w3.org/1999/xhtml" class="mainBox" id="main" chromedir="&locale.dir;">
-        <link rel="stylesheet" type="text/css" href="chrome://pluginproblem/content/pluginProblemContent.css" />
-        <link rel="stylesheet" type="text/css" href="chrome://global/skin/plugins/pluginProblem.css" />
-        <div class="hoverBox">
-          <label>
-            <button class="icon" id="icon"/>
-            <div class="msg msgVulnerabilityStatus" id="vulnerabilityStatus"><!-- set at runtime --></div>
-            <div class="msg msgTapToPlay">&tapToPlayPlugin;</div>
-            <div class="msg msgClickToPlay" id="clickToPlay">&clickToActivatePlugin;</div>
-          </label>
-
-          <div class="msg msgBlocked">&blockedPlugin.label;</div>
-          <div class="msg msgCrashed">
-            <div class="msgCrashedText" id="crashedText"><!-- set at runtime --></div>
-            <!-- link href set at runtime -->
-            <div class="msgReload">&reloadPlugin.pre;<a class="reloadLink" id="reloadLink" href="">&reloadPlugin.middle;</a>&reloadPlugin.post;</div>
-          </div>
-
-          <div class="msg msgManagePlugins"><a class="action-link" id="managePluginsLink" href="">&managePlugins;</a></div>
-          <div class="submitStatus" id="submitStatus">
-            <div class="msg msgPleaseSubmit" id="pleaseSubmit">
-              <textarea class="submitComment"
-                        id="submitComment"
-                        placeholder="&report.comment;"/>
-              <div class="submitURLOptInBox">
-                <label><input class="submitURLOptIn" id="submitURLOptIn" type="checkbox"/> &report.pageURL;</label>
-              </div>
-              <div class="submitButtonBox">
-                <span class="helpIcon" id="helpIcon" role="link"/>
-                <input class="submitButton" type="button"
-                       id="submitButton"
-                       value="&report.please;"/>
-              </div>
-            </div>
-            <div class="msg msgSubmitting">&report.submitting;<span class="throbber"> </span></div>
-            <div class="msg msgSubmitted">&report.submitted;</div>
-            <div class="msg msgNotSubmitted">&report.disabled;</div>
-            <div class="msg msgSubmitFailed">&report.failed;</div>
-            <div class="msg msgNoCrashReport">&report.unavailable;</div>
-          </div>
-          <div class="msg msgCheckForUpdates"><a class="action-link" id="checkForUpdatesLink" href="">&checkForUpdates;</a></div>
-      </div>
-      <button class="closeIcon" id="closeIcon" title="&hidePluginBtn.label;"/>
-    </div>
-    `, "application/xml");
-    this.shadowRoot.importNodeAndAppendChildAt(this.shadowRoot,
-                                               parserDoc.documentElement, true);
-
-    // Notify browser-plugins.js that we were attached, on a delay because
-    // this binding doesn't complete layout until the constructor
-    // completes.
-    this.element.dispatchEvent(new this.window.CustomEvent("PluginBindingAttached"));
-  }
-};
diff --git a/toolkit/mozapps/extensions/Blocklist.jsm b/toolkit/mozapps/extensions/Blocklist.jsm
index cb934518b801..71a0dc3801ce 100644
--- a/toolkit/mozapps/extensions/Blocklist.jsm
+++ b/toolkit/mozapps/extensions/Blocklist.jsm
@@ -1327,7 +1327,7 @@ var Blocklist = {
           addonList.push({
             name: plugin.name,
             version: plugin.version,
-            icon: "chrome://global/skin/plugins/pluginGeneric.svg",
+            icon: "chrome://mozapps/skin/plugins/pluginGeneric.svg",
             disable: false,
             blocked: state == Ci.nsIBlocklistService.STATE_BLOCKED,
             item: plugin,
diff --git a/toolkit/mozapps/extensions/test/browser/browser_bug523784.js b/toolkit/mozapps/extensions/test/browser/browser_bug523784.js
index 10ecc14ce897..22ae0afdf683 100644
--- a/toolkit/mozapps/extensions/test/browser/browser_bug523784.js
+++ b/toolkit/mozapps/extensions/test/browser/browser_bug523784.js
@@ -11,7 +11,7 @@ var args = {
   list: [{
     name: "Bug 523784 softblocked addon",
     version: "1",
-    icon: "chrome://global/skin/plugins/pluginGeneric.svg",
+    icon: "chrome://mozapps/skin/plugins/pluginGeneric.svg",
     disable: false,
     blocked: false,
     url: "http://example.com/bug523784_1",
@@ -96,7 +96,7 @@ function bug523784_test2(win) {
   args.list.push({
     name: "Bug 523784 softblocked addon 2",
     version: "2",
-    icon: "chrome://global/skin/plugins/pluginGeneric.svg",
+    icon: "chrome://mozapps/skin/plugins/pluginGeneric.svg",
     disable: false,
     blocked: false,
     url: "http://example.com/bug523784_2",
@@ -104,7 +104,7 @@ function bug523784_test2(win) {
   args.list.push({
     name: "Bug 523784 softblocked addon 3",
     version: "4",
-    icon: "chrome://global/skin/plugins/pluginGeneric.svg",
+    icon: "chrome://mozapps/skin/plugins/pluginGeneric.svg",
     disable: false,
     blocked: false,
     url: "http://example.com/bug523784_3",
diff --git a/toolkit/pluginproblem/content/pluginProblem.xml b/toolkit/pluginproblem/content/pluginProblem.xml
index cc8131ad8e90..29fc8741cf4b 100644
--- a/toolkit/pluginproblem/content/pluginProblem.xml
+++ b/toolkit/pluginproblem/content/pluginProblem.xml
@@ -18,7 +18,7 @@
 <binding id="pluginProblem" inheritstyle="false" chromeOnlyContent="true" bindToUntrustedContent="true">
     <resources>
         <stylesheet src="chrome://pluginproblem/content/pluginProblemContent.css"/>
-        <stylesheet src="chrome://global/skin/plugins/pluginProblem.css"/>
+        <stylesheet src="chrome://mozapps/skin/plugins/pluginProblem.css"/>
     </resources>
 
     <content>
diff --git a/toolkit/pluginproblem/content/pluginProblemBinding.css b/toolkit/pluginproblem/content/pluginProblemBinding.css
index 2ad78c1ebd24..48506de34445 100644
--- a/toolkit/pluginproblem/content/pluginProblemBinding.css
+++ b/toolkit/pluginproblem/content/pluginProblemBinding.css
@@ -9,6 +9,11 @@ embed:-moz-handler-crashed,
 embed:-moz-handler-clicktoplay,
 embed:-moz-handler-vulnerable-updatable,
 embed:-moz-handler-vulnerable-no-update,
+applet:-moz-handler-blocked,
+applet:-moz-handler-crashed,
+applet:-moz-handler-clicktoplay,
+applet:-moz-handler-vulnerable-updatable,
+applet:-moz-handler-vulnerable-no-update,
 object:-moz-handler-blocked,
 object:-moz-handler-crashed,
 object:-moz-handler-clicktoplay,
@@ -17,21 +22,5 @@ object:-moz-handler-vulnerable-no-update {
     display: inline-block;
     overflow: hidden;
     opacity: 1 !important;
-}
-
-@supports not -moz-bool-pref("dom.ua_widget.enabled") {
-
-    embed:-moz-handler-blocked,
-    embed:-moz-handler-crashed,
-    embed:-moz-handler-clicktoplay,
-    embed:-moz-handler-vulnerable-updatable,
-    embed:-moz-handler-vulnerable-no-update,
-    object:-moz-handler-blocked,
-    object:-moz-handler-crashed,
-    object:-moz-handler-clicktoplay,
-    object:-moz-handler-vulnerable-updatable,
-    object:-moz-handler-vulnerable-no-update {
-        -moz-binding: url('chrome://pluginproblem/content/pluginProblem.xml#pluginProblem') !important;
-    }
-
+    -moz-binding: url('chrome://pluginproblem/content/pluginProblem.xml#pluginProblem') !important;
 }
diff --git a/toolkit/pluginproblem/content/pluginProblemContent.css b/toolkit/pluginproblem/content/pluginProblemContent.css
index fe05087431a5..f65ed6fe7b3a 100644
--- a/toolkit/pluginproblem/content/pluginProblemContent.css
+++ b/toolkit/pluginproblem/content/pluginProblemContent.css
@@ -8,8 +8,7 @@
  * browser-plugins.js (near where this file is mentioned). */
 html|object:not([width]), html|object[width=""],
 html|embed:not([width]), html|embed[width=""],
-html|applet:not([width]), html|applet[width=""],
-:host(:not([width])), :host([width=""]) {
+html|applet:not([width]), html|applet[width=""] {
   width: 240px;
 }
 
@@ -17,29 +16,20 @@ html|applet:not([width]), html|applet[width=""],
  * browser-plugins.js (near where this file is mentioned). */
 html|object:not([height]), html|object[height=""],
 html|embed:not([height]), html|embed[height=""],
-html|applet:not([height]), html|applet[height=""],
-:host(:not([width])), :host([width=""]) {
+html|applet:not([height]), html|applet[height=""] {
   height: 200px;
 }
 
 :-moz-handler-clicktoplay .mainBox,
 :-moz-handler-vulnerable-updatable .mainBox,
 :-moz-handler-vulnerable-no-update .mainBox,
-:-moz-handler-blocked .mainBox,
-:host(:-moz-handler-clicktoplay) .mainBox,
-:host(:-moz-handler-vulnerable-updatable) .mainBox,
-:host(:-moz-handler-vulnerable-no-update) .mainBox,
-:host(:-moz-handler-blocked) .mainBox {
+:-moz-handler-blocked .mainBox {
   -moz-user-focus: normal;
 }
 :-moz-handler-clicktoplay .mainBox:focus,
 :-moz-handler-vulnerable-updatable .mainBox:focus,
 :-moz-handler-vulnerable-no-update .mainBox:focus,
-:-moz-handler-blocked .mainBox:focus,
-:host(:-moz-handler-clicktoplay) .mainBox:focus,
-:host(:-moz-handler-vulnerable-updatable) .mainBox:focus,
-:host(:-moz-handler-vulnerable-no-update) .mainBox:focus,
-:host(:-moz-handler-blocked) .mainBox:focus {
+:-moz-handler-blocked .mainBox:focus {
   outline: 1px dotted;
 }
 
@@ -82,10 +72,7 @@ html|applet:not([height]), html|applet[height=""],
 
 :-moz-handler-clicktoplay .hoverBox,
 :-moz-handler-vulnerable-updatable .hoverBox,
-:-moz-handler-vulnerable-no-update .hoverBox,
-:host(:-moz-handler-clicktoplay) .hoverBox,
-:host(:-moz-handler-vulnerable-updatable) .hoverBox,
-:host(:-moz-handler-vulnerable-no-update) .hoverBox {
+:-moz-handler-vulnerable-no-update .hoverBox {
   cursor: pointer;
 }
 
@@ -107,15 +94,7 @@ html|applet:not([height]), html|applet[height=""],
 :-moz-handler-vulnerable-no-update .msgVulnerabilityStatus,
 :-moz-handler-vulnerable-no-update .msgClickToPlay,
 :-moz-handler-blocked .msgBlocked,
-:-moz-handler-crashed .msgCrashed,
-:host(:-moz-handler-clicktoplay) .msgClickToPlay,
-:host(:-moz-handler-vulnerable-updatable) .msgVulnerabilityStatus,
-:host(:-moz-handler-vulnerable-updatable) .msgCheckForUpdates,
-:host(:-moz-handler-vulnerable-updatable) .msgClickToPlay,
-:host(:-moz-handler-vulnerable-no-update) .msgVulnerabilityStatus,
-:host(:-moz-handler-vulnerable-no-update) .msgClickToPlay,
-:host(:-moz-handler-blocked) .msgBlocked,
-:host(:-moz-handler-crashed) .msgCrashed {
+:-moz-handler-crashed .msgCrashed {
   display: block;
 }
 
diff --git a/toolkit/themes/mobile/jar.mn b/toolkit/themes/mobile/jar.mn
index 52700c5e18c9..2a58e310b295 100644
--- a/toolkit/themes/mobile/jar.mn
+++ b/toolkit/themes/mobile/jar.mn
@@ -48,3 +48,12 @@ toolkit.jar:
   skin/classic/global/media/closedCaptionButton-cc-on.svg  (../shared/media/closedCaptionButton-cc-on.svg)
   skin/classic/global/media/fullscreenEnterButton.svg      (../shared/media/fullscreenEnterButton.svg)
   skin/classic/global/media/fullscreenExitButton.svg       (../shared/media/fullscreenExitButton.svg)
+
+% skin mozapps classic/1.0 %skin/classic/mozapps/
+   skin/classic/mozapps/plugins/pluginProblem.css          (mozapps/plugins/pluginProblem.css)
+
+   skin/classic/mozapps/plugins/contentPluginActivate.png  (mozapps/plugins/contentPluginActivate.png)
+   skin/classic/mozapps/plugins/contentPluginBlocked.png   (mozapps/plugins/contentPluginBlocked.png)
+   skin/classic/mozapps/plugins/contentPluginClose.png     (mozapps/plugins/contentPluginClose.png)
+   skin/classic/mozapps/plugins/contentPluginCrashed.png   (mozapps/plugins/contentPluginCrashed.png)
+   skin/classic/mozapps/plugins/contentPluginStripe.png    (mozapps/plugins/contentPluginStripe.png)
diff --git a/toolkit/themes/mobile/mozapps/plugins/contentPluginActivate.png b/toolkit/themes/mobile/mozapps/plugins/contentPluginActivate.png
new file mode 100644
index 000000000000..eab4439c1352
Binary files /dev/null and b/toolkit/themes/mobile/mozapps/plugins/contentPluginActivate.png differ
diff --git a/toolkit/themes/mobile/mozapps/plugins/contentPluginBlocked.png b/toolkit/themes/mobile/mozapps/plugins/contentPluginBlocked.png
new file mode 100644
index 000000000000..9f59b38e0c7c
Binary files /dev/null and b/toolkit/themes/mobile/mozapps/plugins/contentPluginBlocked.png differ
diff --git a/toolkit/themes/mobile/mozapps/plugins/contentPluginClose.png b/toolkit/themes/mobile/mozapps/plugins/contentPluginClose.png
new file mode 100644
index 000000000000..1b2e94a8085f
Binary files /dev/null and b/toolkit/themes/mobile/mozapps/plugins/contentPluginClose.png differ
diff --git a/toolkit/themes/mobile/mozapps/plugins/contentPluginCrashed.png b/toolkit/themes/mobile/mozapps/plugins/contentPluginCrashed.png
new file mode 100644
index 000000000000..1c0d5b32c78a
Binary files /dev/null and b/toolkit/themes/mobile/mozapps/plugins/contentPluginCrashed.png differ
diff --git a/toolkit/themes/mobile/mozapps/plugins/contentPluginDisabled.png b/toolkit/themes/mobile/mozapps/plugins/contentPluginDisabled.png
new file mode 100644
index 000000000000..529828dc9ec0
Binary files /dev/null and b/toolkit/themes/mobile/mozapps/plugins/contentPluginDisabled.png differ
diff --git a/toolkit/themes/mobile/mozapps/plugins/contentPluginStripe.png b/toolkit/themes/mobile/mozapps/plugins/contentPluginStripe.png
new file mode 100644
index 000000000000..7fda316f3432
Binary files /dev/null and b/toolkit/themes/mobile/mozapps/plugins/contentPluginStripe.png differ
diff --git a/toolkit/themes/mobile/mozapps/plugins/pluginProblem.css b/toolkit/themes/mobile/mozapps/plugins/pluginProblem.css
new file mode 100644
index 000000000000..0e58aa965585
--- /dev/null
+++ b/toolkit/themes/mobile/mozapps/plugins/pluginProblem.css
@@ -0,0 +1,195 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+@namespace html url(http://www.w3.org/1999/xhtml);
+
+/* These styles affect only the bound element, not other page content. */
+.mainBox {
+  font: message-box;
+  font-size: 12px;
+  text-align: center;
+  display: table;
+  width: 100%;
+  height: 100%;
+  background-color: rgb(72,72,72);
+  color: white;
+  -moz-user-select: none;
+}
+
+.hoverBox {
+  display: table-cell;
+  box-sizing: border-box;
+  padding: 5px;
+  vertical-align: middle;
+  width: 100%;
+  height: 100%;
+}
+:-moz-handler-vulnerable-updatable .hoverBox:active,
+:-moz-handler-vulnerable-no-update .hoverBox:active,
+:-moz-handler-clicktoplay .hoverBox:active {
+  background-color: rgb(65, 65, 65);
+}
+
+:-moz-handler-clicktoplay .hoverBox:active .msgTapToPlay,
+:-moz-handler-clicktoplay .hoverBox:active .msgClickToPlay,
+:-moz-handler-vulnerable-updatable .hoverBox:active .msgTapToPlay,
+:-moz-handler-vulnerable-updatable .hoverBox:active .msgClickToPlay,
+:-moz-handler-vulnerable-no-update .hoverBox:active .msgTapToPlay,
+:-moz-handler-vulnerable-no-update .hoverBox:active .msgClickToPlay {
+  color: red;
+}
+
+:-moz-handler-vulnerable-updatable .hoverBox,
+:-moz-handler-vulnerable-no-update .hoverBox,
+:-moz-handler-blocked .hoverBox,
+:-moz-handler-crashed .hoverBox {
+  background-image: url(chrome://mozapps/skin/plugins/contentPluginStripe.png);
+}
+
+html|a {
+  color: white;
+}
+
+.icon {
+  width: 48px;
+  height: 48px;
+  background-position: center;
+  background-repeat: no-repeat;
+  border: none;
+  background-color: transparent;
+  -moz-user-focus: ignore;
+  margin-bottom: 6px;
+}
+
+:-moz-handler-vulnerable-updatable .icon,
+:-moz-handler-vulnerable-no-update .icon {
+  background-image: url(chrome://mozapps/skin/plugins/contentPluginBlocked.png);
+  -moz-user-focus: normal;
+}
+:-moz-handler-blocked .icon {
+  background-image: url(chrome://mozapps/skin/plugins/contentPluginBlocked.png);
+}
+:-moz-handler-clicktoplay .icon {
+  background-image: url(chrome://mozapps/skin/plugins/contentPluginActivate.png);
+  -moz-user-focus: normal;
+}
+:-moz-handler-crashed .icon {
+  background-image: url(chrome://mozapps/skin/plugins/contentPluginCrashed.png);
+}
+
+.throbber {
+  padding-left: 16px; /* width of the background image */
+  background: url(chrome://global/skin/icons/loading.png) no-repeat;
+  margin-left: 5px;
+}
+
+.msgTapToPlay,
+.msgClickToPlay {
+  text-decoration: underline;
+}
+
+@media (-moz-touch-enabled: 0) {
+  :-moz-handler-clicktoplay .msgTapToPlay {
+    display: none;
+  }
+}
+
+@media (-moz-touch-enabled) {
+  :-moz-handler-clicktoplay .msgClickToPlay {
+    display: none;
+  }
+}
+
+.submitStatus div {
+  min-height: 19px; /* height of biggest line (with throbber) */
+}
+
+.submitComment {
+  width: 340px;
+  height: 70px;
+  padding: 5px;
+  border: none;
+  border-radius: 5px;
+  resize: none;
+  font-family: inherit;
+  font-size: inherit;
+}
+
+.submitURLOptInBox {
+  text-align: start;
+}
+
+.submitURLOptIn {
+  margin-left: -1px;
+}
+
+.mainBox[chromedir="rtl"] .submitURLOptIn {
+  margin-left: 0;
+  margin-right: -1px;
+}
+
+.submitButtonBox {
+  margin-top: 7px;
+}
+
+.submitButton {
+  float: right;
+}
+
+.mainBox[chromedir="rtl"] .submitButton {
+  float: left;
+}
+
+.helpIcon {
+  display: inline-block;
+  min-width: 16px;
+  min-height: 16px;
+  background: url(chrome://mozapps/skin/plugins/pluginHelp-16.png) no-repeat;
+  cursor: pointer;
+  float: left;
+}
+
+.mainBox[chromedir="rtl"] .helpIcon {
+  float: right;
+}
+
+.closeIcon {
+  display: block;
+  width: 16px;
+  height: 16px;
+  margin-top: 4px;
+  margin-inline-start: -20px;
+  margin-inline-end: 4px;
+  border: none;
+  background-color: transparent;
+  background-image: url("chrome://mozapps/skin/plugins/contentPluginClose.png");
+  background-repeat: no-repeat;
+}
+
+.closeIcon:hover {
+  background-position: -16px 0;
+}
+
+.closeIcon:hover:active {
+  background-position: -32px 0;
+}
+
+.action-link {
+  display: inline-block;
+  border-radius: 10px;
+  background-color: rgb(35, 35, 35);
+  padding: 2px 8px;
+  margin-top: 7px;
+  text-decoration: none;
+}
+.action-link:active {
+  background-color: rgb(20, 20, 20);
+}
+
+:-moz-handler-vulnerable-updatable .action-link {
+  background-color: #a81b0c;
+}
+:-moz-handler-vulnerable-updatable .action-link:active {
+  background-color: #801409;
+}
diff --git a/toolkit/themes/osx/global/jar.mn b/toolkit/themes/osx/global/jar.mn
index 7689e4fe9f1d..b7dfa83c901f 100644
--- a/toolkit/themes/osx/global/jar.mn
+++ b/toolkit/themes/osx/global/jar.mn
@@ -65,4 +65,3 @@ toolkit.jar:
 * skin/classic/global/in-content/common.css                          (in-content/common.css)
 * skin/classic/global/in-content/info-pages.css                      (in-content/info-pages.css)
   skin/classic/global/tree/columnpicker.gif                          (tree/columnpicker.gif)
-  skin/classic/global/plugins/pluginHelp-16.png                      (plugins/pluginHelp-16.png)
diff --git a/toolkit/themes/osx/mozapps/jar.mn b/toolkit/themes/osx/mozapps/jar.mn
index 23388bc61892..9589b8f56de9 100644
--- a/toolkit/themes/osx/mozapps/jar.mn
+++ b/toolkit/themes/osx/mozapps/jar.mn
@@ -14,6 +14,7 @@ toolkit.jar:
   skin/classic/mozapps/extensions/heart.png                       (extensions/heart.png)
 * skin/classic/mozapps/extensions/extensions.css                  (extensions/extensions.css)
   skin/classic/mozapps/extensions/blocklist.css                   (extensions/blocklist.css)
+  skin/classic/mozapps/plugins/pluginHelp-16.png                  (plugins/pluginHelp-16.png)
   skin/classic/mozapps/profile/profileSelection.css               (profile/profileSelection.css)
   skin/classic/mozapps/update/buttons.png                         (update/buttons.png)
 * skin/classic/mozapps/update/updates.css                         (update/updates.css)
diff --git a/toolkit/themes/osx/global/plugins/pluginHelp-16.png b/toolkit/themes/osx/mozapps/plugins/pluginHelp-16.png
similarity index 100%
rename from toolkit/themes/osx/global/plugins/pluginHelp-16.png
rename to toolkit/themes/osx/mozapps/plugins/pluginHelp-16.png
diff --git a/toolkit/themes/shared/extensions/extensions.inc.css b/toolkit/themes/shared/extensions/extensions.inc.css
index 6e22f116a23c..b74b034b3bdf 100644
--- a/toolkit/themes/shared/extensions/extensions.inc.css
+++ b/toolkit/themes/shared/extensions/extensions.inc.css
@@ -362,7 +362,7 @@ button.warning {
 }
 
 .addon-view[type="plugin"] .icon {
-  list-style-image: url("chrome://global/skin/plugins/pluginGeneric.svg");
+  list-style-image: url("chrome://mozapps/skin/plugins/pluginGeneric.svg");
 }
 
 .addon-view[type="dictionary"] .icon {
diff --git a/toolkit/themes/shared/jar.inc.mn b/toolkit/themes/shared/jar.inc.mn
index fd5946f65a2a..9086e0129efb 100644
--- a/toolkit/themes/shared/jar.inc.mn
+++ b/toolkit/themes/shared/jar.inc.mn
@@ -96,10 +96,3 @@ toolkit.jar:
 #ifdef MOZ_PLACES
   skin/classic/mozapps/places/defaultFavicon.svg           (../../shared/places/defaultFavicon.svg)
 #endif
-  skin/classic/global/plugins/plugin.svg                    (../../shared/plugins/plugin.svg)
-  skin/classic/global/plugins/plugin-blocked.svg            (../../shared/plugins/plugin-blocked.svg)
-  skin/classic/global/plugins/pluginGeneric.svg             (../../shared/extensions/category-plugins.svg)
-  skin/classic/global/plugins/pluginProblem.css             (../../shared/plugins/pluginProblem.css)
-  skin/classic/global/plugins/contentPluginBlocked.png      (../../shared/plugins/contentPluginBlocked.png)
-  skin/classic/global/plugins/contentPluginCrashed.png      (../../shared/plugins/contentPluginCrashed.png)
-  skin/classic/global/plugins/contentPluginStripe.png       (../../shared/plugins/contentPluginStripe.png)
diff --git a/toolkit/themes/shared/mozapps.inc.mn b/toolkit/themes/shared/mozapps.inc.mn
index e3813ac0925c..c0dd703b7218 100644
--- a/toolkit/themes/shared/mozapps.inc.mn
+++ b/toolkit/themes/shared/mozapps.inc.mn
@@ -23,13 +23,20 @@
   skin/classic/mozapps/extensions/alerticon-info-positive.svg (../../shared/extensions/alerticon-info-positive.svg)
   skin/classic/mozapps/extensions/alerticon-info-negative.svg (../../shared/extensions/alerticon-info-negative.svg)
   skin/classic/mozapps/extensions/category-legacy.svg        (../../shared/extensions/category-legacy.svg)
+  skin/classic/mozapps/plugins/plugin.svg                    (../../shared/plugins/plugin.svg)
+  skin/classic/mozapps/plugins/plugin-blocked.svg            (../../shared/plugins/plugin-blocked.svg)
+  skin/classic/mozapps/plugins/pluginGeneric.svg             (../../shared/extensions/category-plugins.svg)
+  skin/classic/mozapps/plugins/pluginProblem.css             (../../shared/plugins/pluginProblem.css)
   skin/classic/mozapps/aboutNetworking.css                   (../../shared/aboutNetworking.css)
 #ifndef ANDROID
   skin/classic/mozapps/aboutProfiles.css                     (../../shared/aboutProfiles.css)
 #endif
   skin/classic/mozapps/aboutServiceWorkers.css               (../../shared/aboutServiceWorkers.css)
+  skin/classic/mozapps/plugins/contentPluginBlocked.png      (../../shared/plugins/contentPluginBlocked.png)
+  skin/classic/mozapps/plugins/contentPluginCrashed.png      (../../shared/plugins/contentPluginCrashed.png)
+  skin/classic/mozapps/plugins/contentPluginStripe.png       (../../shared/plugins/contentPluginStripe.png)
 
-% override chrome://mozapps/skin/extensions/category-plugins.svg          chrome://global/skin/plugins/pluginGeneric.svg
+% override chrome://mozapps/skin/extensions/category-plugins.svg          chrome://mozapps/skin/plugins/pluginGeneric.svg
 % override chrome://mozapps/skin/extensions/category-extensions.svg       chrome://mozapps/skin/extensions/extensionGeneric.svg
 % override chrome://mozapps/skin/extensions/category-languages.svg        chrome://mozapps/skin/extensions/localeGeneric.svg
 % override chrome://mozapps/skin/extensions/category-themes.svg           chrome://mozapps/skin/extensions/themeGeneric.svg
diff --git a/toolkit/themes/shared/non-mac.jar.inc.mn b/toolkit/themes/shared/non-mac.jar.inc.mn
index 3d0c9d08bd5e..51448d2132d1 100644
--- a/toolkit/themes/shared/non-mac.jar.inc.mn
+++ b/toolkit/themes/shared/non-mac.jar.inc.mn
@@ -26,7 +26,6 @@
   skin/classic/global/icons/question-64.png                (../../windows/global/icons/question-64.png)
   skin/classic/global/icons/search-textbox.svg             (../../windows/global/icons/search-textbox.svg)
   skin/classic/global/tree/columnpicker.gif                (../../windows/global/tree/columnpicker.gif)
-  skin/classic/global/plugins/pluginHelp-16.png            (../../windows/global/plugins/pluginHelp-16.png)
 
   skin/classic/mozapps/downloads/downloadButtons.png         (../../windows/mozapps/downloads/downloadButtons.png)
   skin/classic/mozapps/downloads/unknownContentType.css      (../../windows/mozapps/downloads/unknownContentType.css)
@@ -36,6 +35,7 @@
   skin/classic/mozapps/extensions/rating-not-won.png         (../../windows/mozapps/extensions/rating-not-won.png)
   skin/classic/mozapps/extensions/cancel.png                 (../../windows/mozapps/extensions/cancel.png)
   skin/classic/mozapps/handling/handling.css                 (../../windows/mozapps/handling/handling.css)
+  skin/classic/mozapps/plugins/pluginHelp-16.png             (../../windows/mozapps/plugins/pluginHelp-16.png)
   skin/classic/mozapps/profile/profileSelection.css          (../../windows/mozapps/profile/profileSelection.css)
   skin/classic/mozapps/update/downloadButtons.png            (../../windows/mozapps/update/downloadButtons.png)
 
diff --git a/toolkit/themes/shared/plugins/pluginProblem.css b/toolkit/themes/shared/plugins/pluginProblem.css
index a8654a1ee73f..29636af0839b 100644
--- a/toolkit/themes/shared/plugins/pluginProblem.css
+++ b/toolkit/themes/shared/plugins/pluginProblem.css
@@ -32,28 +32,20 @@
   height: 100%;
 }
 :-moz-handler-vulnerable-updatable .hoverBox:active,
-:-moz-handler-vulnerable-no-update .hoverBox:active,
-:host(:-moz-handler-vulnerable-updatable) .hoverBox:active,
-:host(:-moz-handler-vulnerable-no-update) .hoverBox:active {
+:-moz-handler-vulnerable-no-update .hoverBox:active {
   background-color: rgb(65, 65, 65);
 }
 
 :-moz-handler-vulnerable-updatable .hoverBox:active .msgClickToPlay,
-:-moz-handler-vulnerable-no-update .hoverBox:active .msgClickToPlay,
-:host(:-moz-handler-vulnerable-updatable) .hoverBox:active .msgClickToPlay,
-:host(:-moz-handler-vulnerable-no-update) .hoverBox:active .msgClickToPlay {
+:-moz-handler-vulnerable-no-update .hoverBox:active .msgClickToPlay {
   color: red;
 }
 
 :-moz-handler-vulnerable-updatable .hoverBox,
 :-moz-handler-vulnerable-no-update .hoverBox,
 :-moz-handler-blocked .hoverBox,
-:-moz-handler-crashed .hoverBox,
-:host(:-moz-handler-vulnerable-updatable) .hoverBox,
-:host(:-moz-handler-vulnerable-no-update) .hoverBox,
-:host(:-moz-handler-blocked) .hoverBox,
-:host(:-moz-handler-crashed) .hoverBox {
-  background-image: url(chrome://global/skin/plugins/contentPluginStripe.png);
+:-moz-handler-crashed .hoverBox {
+  background-image: url(chrome://mozapps/skin/plugins/contentPluginStripe.png);
 }
 
 html|a {
@@ -74,25 +66,20 @@ html|a {
 }
 
 :-moz-handler-vulnerable-updatable .icon,
-:-moz-handler-vulnerable-no-update .icon,
-:host(:-moz-handler-vulnerable-updatable) .icon,
-:host(:-moz-handler-vulnerable-no-update) .icon {
-  background-image: url(chrome://global/skin/plugins/contentPluginBlocked.png);
+:-moz-handler-vulnerable-no-update .icon {
+  background-image: url(chrome://mozapps/skin/plugins/contentPluginBlocked.png);
   -moz-user-focus: normal;
 }
-:-moz-handler-blocked .icon,
-:host(:-moz-handler-blocked) .icon {
-  background-image: url(chrome://global/skin/plugins/contentPluginBlocked.png);
+:-moz-handler-blocked .icon {
+  background-image: url(chrome://mozapps/skin/plugins/contentPluginBlocked.png);
 }
-:-moz-handler-clicktoplay .icon,
-:host(:-moz-handler-clicktoplay) .icon {
-  background-image: url(chrome://global/skin/plugins/plugin.svg);
+:-moz-handler-clicktoplay .icon {
+  background-image: url(chrome://mozapps/skin/plugins/plugin.svg);
   fill: var(--grey-10);
   -moz-user-focus: normal;
 }
-:-moz-handler-crashed .icon,
-:host(:-moz-handler-crashed) .icon {
-  background-image: url(chrome://global/skin/plugins/contentPluginCrashed.png);
+:-moz-handler-crashed .icon {
+  background-image: url(chrome://mozapps/skin/plugins/contentPluginCrashed.png);
 }
 
 .throbber {
@@ -109,8 +96,7 @@ html|a {
 }
 
 /* on desktop, don't ever show the tap-to-play UI: that is for mobile only */
-:-moz-handler-clicktoplay .msgTapToPlay,
-:host(:-moz-handler-clicktoplay) .msgTapToPlay {
+:-moz-handler-clicktoplay .msgTapToPlay {
   display: none;
 }
 
@@ -158,7 +144,7 @@ html|a {
   display: inline-block;
   min-width: 16px;
   min-height: 16px;
-  background: url(chrome://global/skin/plugins/pluginHelp-16.png) no-repeat;
+  background: url(chrome://mozapps/skin/plugins/pluginHelp-16.png) no-repeat;
   cursor: pointer;
   float: left;
 }
@@ -204,12 +190,10 @@ html|a {
   background-color: rgb(20, 20, 20);
 }
 
-:-moz-handler-vulnerable-updatable .action-link,
-:host(:-moz-handler-vulnerable-updatable) .action-link {
+:-moz-handler-vulnerable-updatable .action-link {
   background-color: #a81b0c;
 }
-:-moz-handler-vulnerable-updatable .action-link:active,
-:host(:-moz-handler-vulnerable-updatable) .action-link:active {
+:-moz-handler-vulnerable-updatable .action-link:active {
   background-color: #801409;
 }
 
@@ -220,49 +204,39 @@ html|a {
  * redesign for all cases, we can change the CSS directly
  * above instead of writing these super-specific rules.
  */
-:-moz-handler-clicktoplay .mainBox,
-:host(:-moz-handler-clicktoplay) .mainBox {
+:-moz-handler-clicktoplay .mainBox {
   background-color: var(--grey-70);
 }
 
-:-moz-handler-clicktoplay .msgClickToPlay,
-:host(:-moz-handler-clicktoplay) .msgClickToPlay {
+:-moz-handler-clicktoplay .msgClickToPlay {
   font-size: 13px;
 }
 
-:-moz-handler-clicktoplay .mainBox[sizing=blank] .hoverBox,
-:host(:-moz-handler-clicktoplay) .mainBox[sizing=blank] .hoverBox {
+:-moz-handler-clicktoplay .mainBox[sizing=blank] .hoverBox {
   visibility: hidden;
 }
 
-:-moz-handler-clicktoplay .mainBox[sizing=tiny] .icon,
-:host(:-moz-handler-clicktoplay) .mainBox[sizing=tiny] .icon {
+:-moz-handler-clicktoplay .mainBox[sizing=tiny] .icon {
   width: 16px;
   height: 16px;
 }
 
-:-moz-handler-clicktoplay .mainBox[sizing=reduced] .icon,
-:host(:-moz-handler-clicktoplay) .mainBox[sizing=reduced] .icon {
+:-moz-handler-clicktoplay .mainBox[sizing=reduced] .icon {
   width: 32px;
   height: 32px;
 }
 
 :-moz-handler-clicktoplay .mainBox[sizing=blank] .closeIcon,
 :-moz-handler-clicktoplay .mainBox[sizing=tiny] .closeIcon,
-:-moz-handler-clicktoplay .mainBox[sizing=reduced] .closeIcon,
-:host(:-moz-handler-clicktoplay) .mainBox[sizing=blank] .closeIcon,
-:host(:-moz-handler-clicktoplay) .mainBox[sizing=tiny] .closeIcon,
-:host(:-moz-handler-clicktoplay) .mainBox[sizing=reduced] .closeIcon {
+:-moz-handler-clicktoplay .mainBox[sizing=reduced] .closeIcon {
   display: none;
 }
 
-:-moz-handler-clicktoplay .mainBox[notext] .msgClickToPlay,
-:host(:-moz-handler-clicktoplay) .mainBox[notext] .msgClickToPlay {
+:-moz-handler-clicktoplay .mainBox[notext] .msgClickToPlay {
   display: none;
 }
 
-:-moz-handler-clicktoplay .mainBox[notext] .icon,
-:host(:-moz-handler-clicktoplay) .mainBox[notext] .icon {
+:-moz-handler-clicktoplay .mainBox[notext] .icon {
   /* Override a `margin-bottom: 6px` now that .msgClickToPlay
    * below the icon is no longer shown, in order to achieve
    * a perfect vertical centering of the icon.
diff --git a/toolkit/themes/windows/global/plugins/pluginHelp-16.png b/toolkit/themes/windows/mozapps/plugins/pluginHelp-16.png
similarity index 100%
rename from toolkit/themes/windows/global/plugins/pluginHelp-16.png
rename to toolkit/themes/windows/mozapps/plugins/pluginHelp-16.png