diff --git a/browser/actors/ClickHandlerChild.jsm b/browser/actors/ClickHandlerChild.jsm
index 49aa06a7f43c..d5f7f31f3280 100644
--- a/browser/actors/ClickHandlerChild.jsm
+++ b/browser/actors/ClickHandlerChild.jsm
@@ -7,6 +7,11 @@ var EXPORTED_SYMBOLS = ["ClickHandlerChild"];
 
 const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
 
+ChromeUtils.defineModuleGetter(
+  this,
+  "BrowserUtils",
+  "resource://gre/modules/BrowserUtils.jsm"
+);
 ChromeUtils.defineModuleGetter(
   this,
   "PrivateBrowsingUtils",
@@ -97,10 +102,7 @@ class ClickHandlerChild extends JSWindowActorChild {
 
     if (href) {
       try {
-        Services.scriptSecurityManager.checkLoadURIStrWithPrincipal(
-          principal,
-          href
-        );
+        BrowserUtils.urlSecurityCheck(href, principal);
       } catch (e) {
         return;
       }
diff --git a/browser/actors/ContextMenuChild.jsm b/browser/actors/ContextMenuChild.jsm
index e4df8f49e890..2b2635fb6d8e 100644
--- a/browser/actors/ContextMenuChild.jsm
+++ b/browser/actors/ContextMenuChild.jsm
@@ -17,11 +17,11 @@ XPCOMUtils.defineLazyGlobalGetters(this, ["URL"]);
 
 XPCOMUtils.defineLazyModuleGetters(this, {
   E10SUtils: "resource://gre/modules/E10SUtils.jsm",
+  BrowserUtils: "resource://gre/modules/BrowserUtils.jsm",
   SpellCheckHelper: "resource://gre/modules/InlineSpellChecker.jsm",
   LoginManagerChild: "resource://gre/modules/LoginManagerChild.jsm",
   WebNavigationFrames: "resource://gre/modules/WebNavigationFrames.jsm",
   PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.jsm",
-  SelectionUtils: "resource://gre/modules/SelectionUtils.jsm",
   InlineSpellCheckerContent:
     "resource://gre/modules/InlineSpellCheckerContent.jsm",
   ContentDOMReference: "resource://gre/modules/ContentDOMReference.jsm",
@@ -237,9 +237,9 @@ class ContextMenuChild extends JSWindowActorChild {
 
         if (!disable) {
           try {
-            Services.scriptSecurityManager.checkLoadURIWithPrincipal(
-              target.ownerDocument.nodePrincipal,
-              target.currentURI
+            BrowserUtils.urlSecurityCheck(
+              target.currentURI.spec,
+              target.ownerDocument.nodePrincipal
             );
             let canvas = this.document.createElement("canvas");
             canvas.width = target.naturalWidth;
@@ -614,7 +614,7 @@ class ContextMenuChild extends JSWindowActorChild {
       } catch (e) {}
     }
 
-    let selectionInfo = SelectionUtils.getSelectionDetails(this.contentWindow);
+    let selectionInfo = BrowserUtils.getSelectionDetails(this.contentWindow);
     let loadContext = this.docShell.QueryInterface(Ci.nsILoadContext);
     let userContextId = loadContext.originAttributes.userContextId;
 
diff --git a/browser/actors/EncryptedMediaParent.jsm b/browser/actors/EncryptedMediaParent.jsm
index a0394a088888..ddddda997b09 100644
--- a/browser/actors/EncryptedMediaParent.jsm
+++ b/browser/actors/EncryptedMediaParent.jsm
@@ -14,8 +14,8 @@ const { XPCOMUtils } = ChromeUtils.import(
 
 ChromeUtils.defineModuleGetter(
   this,
-  "BrowserUIUtils",
-  "resource:///modules/BrowserUIUtils.jsm"
+  "BrowserUtils",
+  "resource://gre/modules/BrowserUtils.jsm"
 );
 
 XPCOMUtils.defineLazyGetter(this, "gBrandBundle", function() {
@@ -73,7 +73,7 @@ class EncryptedMediaParent extends JSWindowActorParent {
     let link = document.createXULElement("label", { is: "text-link" });
     link.setAttribute("href", baseURL + "drm-content");
     link.textContent = text;
-    return BrowserUIUtils.getLocalizedFragment(document, mainMessage, link);
+    return BrowserUtils.getLocalizedFragment(document, mainMessage, link);
   }
 
   getMessageWithBrandName(aNotificationId) {
diff --git a/browser/actors/FormValidationChild.jsm b/browser/actors/FormValidationChild.jsm
index 787aec54e723..180e79fc93ae 100644
--- a/browser/actors/FormValidationChild.jsm
+++ b/browser/actors/FormValidationChild.jsm
@@ -10,8 +10,8 @@
 
 var EXPORTED_SYMBOLS = ["FormValidationChild"];
 
-const { LayoutUtils } = ChromeUtils.import(
-  "resource://gre/modules/LayoutUtils.jsm"
+const { BrowserUtils } = ChromeUtils.import(
+  "resource://gre/modules/BrowserUtils.jsm"
 );
 const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
 
@@ -154,7 +154,7 @@ class FormValidationChild extends JSWindowActorChild {
 
     panelData.message = this._validationMessage;
 
-    panelData.screenRect = LayoutUtils.getElementBoundingScreenRect(aElement);
+    panelData.screenRect = BrowserUtils.getElementBoundingScreenRect(aElement);
 
     // We want to show the popup at the middle of checkbox and radio buttons
     // and where the content begin for the other elements.
diff --git a/browser/actors/PluginChild.jsm b/browser/actors/PluginChild.jsm
index 76dd5f58fd18..7210c0a88c8a 100644
--- a/browser/actors/PluginChild.jsm
+++ b/browser/actors/PluginChild.jsm
@@ -9,6 +9,9 @@ var EXPORTED_SYMBOLS = ["PluginChild"];
 const { AppConstants } = ChromeUtils.import(
   "resource://gre/modules/AppConstants.jsm"
 );
+const { BrowserUtils } = ChromeUtils.import(
+  "resource://gre/modules/BrowserUtils.jsm"
+);
 const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
 const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
@@ -41,37 +44,6 @@ const OVERLAY_DISPLAY = {
 // definition.
 const kSubmitMsg = "PluginParent:NPAPIPluginCrashReportSubmitted";
 
-/**
- * Map the plugin's name to a filtered version more suitable for UI.
- *
- * N.B. This should be completely dead code at this point.
- *
- * @param aName The full-length name string of the plugin.
- * @return the simplified name string.
- */
-function makeNicePluginName(aName) {
-  if (aName == "Shockwave Flash") {
-    return "Adobe Flash";
-  }
-  // Regex checks if aName begins with "Java" + non-letter char
-  if (/^Java\W/.test(aName)) {
-    return "Java";
-  }
-
-  // Clean up the plugin name by stripping off parenthetical clauses,
-  // trailing version numbers or "plugin".
-  // EG, "Foo Bar (Linux) Plugin 1.23_02" --> "Foo Bar"
-  // Do this by first stripping the numbers, etc. off the end, and then
-  // removing "Plugin" (and then trimming to get rid of any whitespace).
-  // (Otherwise, something like "Java(TM) Plug-in 1.7.0_07" gets mangled)
-  let newName = aName
-    .replace(/\(.*?\)/g, "")
-    .replace(/[\s\d\.\-\_\(\)]+$/, "")
-    .replace(/\bplug-?in\b/i, "")
-    .trim();
-  return newName;
-}
-
 class PluginChild extends JSWindowActorChild {
   constructor() {
     super();
@@ -167,7 +139,7 @@ class PluginChild extends JSWindowActorChild {
   _getPluginInfo(pluginElement) {
     if (this.isKnownPlugin(pluginElement)) {
       let pluginTag = gPluginHost.getPluginTagForType(pluginElement.actualType);
-      let pluginName = makeNicePluginName(pluginTag.name);
+      let pluginName = BrowserUtils.makeNicePluginName(pluginTag.name);
       let fallbackType = pluginElement.defaultFallbackType;
       let permissionString = gPluginHost.getPermissionStringForType(
         pluginElement.actualType
@@ -197,7 +169,7 @@ class PluginChild extends JSWindowActorChild {
     // nsIObjectLoadingContent to check.
     let fallbackType = Ci.nsIObjectLoadingContent.PLUGIN_CLICK_TO_PLAY;
     if (pluginTag) {
-      let pluginName = makeNicePluginName(pluginTag.name);
+      let pluginName = BrowserUtils.makeNicePluginName(pluginTag.name);
       let permissionString = gPluginHost.getPermissionStringForTag(pluginTag);
       return { pluginTag, pluginName, permissionString, fallbackType };
     }
diff --git a/browser/actors/PluginParent.jsm b/browser/actors/PluginParent.jsm
index 9aa6588d076f..05f8936cc336 100644
--- a/browser/actors/PluginParent.jsm
+++ b/browser/actors/PluginParent.jsm
@@ -22,6 +22,11 @@ XPCOMUtils.defineLazyServiceGetter(
   "nsIPluginHost"
 );
 
+ChromeUtils.defineModuleGetter(
+  this,
+  "BrowserUtils",
+  "resource://gre/modules/BrowserUtils.jsm"
+);
 ChromeUtils.defineModuleGetter(
   this,
   "CrashSubmit",
@@ -42,37 +47,6 @@ const {
   PLUGIN_CLICK_TO_PLAY_QUIET,
 } = Ci.nsIObjectLoadingContent;
 
-/**
- * Map the plugin's name to a filtered version more suitable for UI.
- *
- * N.B. This should be completely dead code at this point.
- *
- * @param aName The full-length name string of the plugin.
- * @return the simplified name string.
- */
-function makeNicePluginName(aName) {
-  if (aName == "Shockwave Flash") {
-    return "Adobe Flash";
-  }
-  // Regex checks if aName begins with "Java" + non-letter char
-  if (/^Java\W/.test(aName)) {
-    return "Java";
-  }
-
-  // Clean up the plugin name by stripping off parenthetical clauses,
-  // trailing version numbers or "plugin".
-  // EG, "Foo Bar (Linux) Plugin 1.23_02" --> "Foo Bar"
-  // Do this by first stripping the numbers, etc. off the end, and then
-  // removing "Plugin" (and then trimming to get rid of any whitespace).
-  // (Otherwise, something like "Java(TM) Plug-in 1.7.0_07" gets mangled)
-  let newName = aName
-    .replace(/\(.*?\)/g, "")
-    .replace(/[\s\d\.\-\_\(\)]+$/, "")
-    .replace(/\bplug-?in\b/i, "")
-    .trim();
-  return newName;
-}
-
 const PluginManager = {
   _initialized: false,
 
@@ -155,7 +129,7 @@ const PluginManager = {
 
     let runID = propertyBag.getPropertyAsUint32("runID");
     let uglyPluginName = propertyBag.getPropertyAsAString("pluginName");
-    let pluginName = makeNicePluginName(uglyPluginName);
+    let pluginName = BrowserUtils.makeNicePluginName(uglyPluginName);
     let pluginDumpID = propertyBag.getPropertyAsAString("pluginDumpID");
 
     let state;
diff --git a/browser/base/content/browser-addons.js b/browser/base/content/browser-addons.js
index 0afcdcef9d62..78b94a68d6eb 100644
--- a/browser/base/content/browser-addons.js
+++ b/browser/base/content/browser-addons.js
@@ -631,7 +631,7 @@ var gXPInstallObserver = {
             );
             let b = doc.createElementNS("http://www.w3.org/1999/xhtml", "b");
             b.textContent = options.name;
-            let fragment = BrowserUIUtils.getLocalizedFragment(doc, text, b);
+            let fragment = BrowserUtils.getLocalizedFragment(doc, text, b);
             message.appendChild(fragment);
           } else {
             message.textContent = gNavigatorBundle.getString(
diff --git a/browser/base/content/browser-places.js b/browser/base/content/browser-places.js
index 62ea03141829..83ac8763c8fe 100644
--- a/browser/base/content/browser-places.js
+++ b/browser/base/content/browser-places.js
@@ -2188,7 +2188,7 @@ var BookmarkingUI = {
     ) {
       let isBookmarked = this._itemGuids.size > 0;
       if (!isBookmarked) {
-        BrowserUIUtils.setToolbarButtonHeightProperty(this.star);
+        BrowserUtils.setToolbarButtonHeightProperty(this.star);
         // there are no other animations on this element, so we can simply
         // listen for animationend with the "once" option to clean up
         let animatableBox = document.getElementById(
diff --git a/browser/base/content/browser.js b/browser/base/content/browser.js
index 86d2383121c5..36c730e64b73 100644
--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -22,8 +22,6 @@ XPCOMUtils.defineLazyModuleGetters(this, {
   NewTabPagePreloading: "resource:///modules/NewTabPagePreloading.jsm",
   BrowserSearchTelemetry: "resource:///modules/BrowserSearchTelemetry.jsm",
   BrowserUsageTelemetry: "resource:///modules/BrowserUsageTelemetry.jsm",
-  BrowserTelemetryUtils: "resource://gre/modules/BrowserTelemetryUtils.jsm",
-  BrowserUIUtils: "resource:///modules/BrowserUIUtils.jsm",
   BrowserUtils: "resource://gre/modules/BrowserUtils.jsm",
   BrowserWindowTracker: "resource:///modules/BrowserWindowTracker.jsm",
   CFRPageActions: "resource://activity-stream/lib/CFRPageActions.jsm",
@@ -4933,7 +4931,7 @@ var XULBrowserWindow = {
       );
 
       if (UrlbarPrefs.get("trimURLs")) {
-        url = BrowserUIUtils.trimURL(url);
+        url = BrowserUtils.trimURL(url);
       }
     }
 
@@ -5122,7 +5120,7 @@ var XULBrowserWindow = {
         aFlags & Ci.nsIWebProgressListener.LOCATION_CHANGE_SAME_DOCUMENT;
       if (
         (location == "about:blank" &&
-          BrowserUIUtils.checkEmptyPageOrigin(gBrowser.selectedBrowser)) ||
+          BrowserUtils.checkEmptyPageOrigin(gBrowser.selectedBrowser)) ||
         location == ""
       ) {
         // Second condition is for new tabs, otherwise
@@ -5585,7 +5583,7 @@ var CombinedStopReload = {
 
     this._cancelTransition();
     if (shouldAnimate) {
-      BrowserUIUtils.setToolbarButtonHeightProperty(this.stopReloadContainer);
+      BrowserUtils.setToolbarButtonHeightProperty(this.stopReloadContainer);
       this.stopReloadContainer.setAttribute("animate", "true");
     } else {
       this.stopReloadContainer.removeAttribute("animate");
@@ -5608,7 +5606,7 @@ var CombinedStopReload = {
       this.stopReloadContainer.closest("#nav-bar-customization-target");
 
     if (shouldAnimate) {
-      BrowserUIUtils.setToolbarButtonHeightProperty(this.stopReloadContainer);
+      BrowserUtils.setToolbarButtonHeightProperty(this.stopReloadContainer);
       this.stopReloadContainer.setAttribute("animate", "true");
     } else {
       this.stopReloadContainer.removeAttribute("animate");
@@ -5719,7 +5717,7 @@ var TabsProgressListener = {
         ) {
           if (recordLoadTelemetry) {
             TelemetryStopwatch.finish(histogram, aBrowser);
-            BrowserTelemetryUtils.recordSiteOriginTelemetry(browserWindows());
+            BrowserUtils.recordSiteOriginTelemetry(browserWindows());
           }
         }
       } else if (
diff --git a/browser/base/content/nsContextMenu.js b/browser/base/content/nsContextMenu.js
index ec0a03e6ba83..8599c52a2b6b 100644
--- a/browser/base/content/nsContextMenu.js
+++ b/browser/base/content/nsContextMenu.js
@@ -255,12 +255,8 @@ class nsContextMenu {
       this.selectionInfo = this.contentData.selectionInfo;
       this.actor = this.contentData.actor;
     } else {
-      const { SelectionUtils } = ChromeUtils.import(
-        "resource://gre/modules/SelectionUtils.jsm"
-      );
-
       this.browser = this.ownerDoc.defaultView.docShell.chromeEventHandler;
-      this.selectionInfo = SelectionUtils.getSelectionDetails(window);
+      this.selectionInfo = BrowserUtils.getSelectionDetails(window);
       this.actor = this.browser.browsingContext.currentWindowGlobal.getActor(
         "ContextMenu"
       );
diff --git a/browser/base/content/tabbrowser-tab.js b/browser/base/content/tabbrowser-tab.js
index 9b36d5721b7e..e8322329933e 100644
--- a/browser/base/content/tabbrowser-tab.js
+++ b/browser/base/content/tabbrowser-tab.js
@@ -227,7 +227,7 @@
         return false;
       }
 
-      if (!BrowserUIUtils.checkEmptyPageOrigin(browser)) {
+      if (!BrowserUtils.checkEmptyPageOrigin(browser)) {
         return false;
       }
 
diff --git a/browser/components/BrowserGlue.jsm b/browser/components/BrowserGlue.jsm
index e8f1638cc279..c0650b2c72e9 100644
--- a/browser/components/BrowserGlue.jsm
+++ b/browser/components/BrowserGlue.jsm
@@ -31,7 +31,7 @@ XPCOMUtils.defineLazyModuleGetters(this, {
   BookmarkJSONUtils: "resource://gre/modules/BookmarkJSONUtils.jsm",
   BrowserSearchTelemetry: "resource:///modules/BrowserSearchTelemetry.jsm",
   BrowserUsageTelemetry: "resource:///modules/BrowserUsageTelemetry.jsm",
-  BrowserUIUtils: "resource:///modules/BrowserUIUtils.jsm",
+  BrowserUtils: "resource://gre/modules/BrowserUtils.jsm",
   BrowserWindowTracker: "resource:///modules/BrowserWindowTracker.jsm",
   ContextualIdentityService:
     "resource://gre/modules/ContextualIdentityService.jsm",
@@ -3950,7 +3950,7 @@ BrowserGlue.prototype = {
         // same way that the url bar would.
         body = URIs[0].uri.replace(/([?#]).*$/, "$1");
         let wasTruncated = body.length < URIs[0].uri.length;
-        body = BrowserUIUtils.trimURL(body);
+        body = BrowserUtils.trimURL(body);
         if (wasTruncated) {
           body = bundle.formatStringFromName(
             "singleTabArrivingWithTruncatedURL.body",
diff --git a/browser/components/customizableui/CustomizeMode.jsm b/browser/components/customizableui/CustomizeMode.jsm
index 7b97b88e79b1..16b33ae73bf5 100644
--- a/browser/components/customizableui/CustomizeMode.jsm
+++ b/browser/components/customizableui/CustomizeMode.jsm
@@ -52,8 +52,8 @@ ChromeUtils.defineModuleGetter(
 );
 ChromeUtils.defineModuleGetter(
   this,
-  "BrowserUIUtils",
-  "resource:///modules/BrowserUIUtils.jsm"
+  "BrowserUtils",
+  "resource://gre/modules/BrowserUtils.jsm"
 );
 ChromeUtils.defineModuleGetter(
   this,
@@ -791,7 +791,7 @@ CustomizeMode.prototype = {
     }
     if (!this.window.gReduceMotion) {
       let overflowButton = this.$("nav-bar-overflow-button");
-      BrowserUIUtils.setToolbarButtonHeightProperty(overflowButton).then(() => {
+      BrowserUtils.setToolbarButtonHeightProperty(overflowButton).then(() => {
         overflowButton.setAttribute("animate", "true");
         overflowButton.addEventListener("animationend", function onAnimationEnd(
           event
diff --git a/browser/components/extensions/ExtensionControlledPopup.jsm b/browser/components/extensions/ExtensionControlledPopup.jsm
index 2f61c75bada3..8bd63c6c1001 100644
--- a/browser/components/extensions/ExtensionControlledPopup.jsm
+++ b/browser/components/extensions/ExtensionControlledPopup.jsm
@@ -34,8 +34,8 @@ ChromeUtils.defineModuleGetter(
 );
 ChromeUtils.defineModuleGetter(
   this,
-  "BrowserUIUtils",
-  "resource:///modules/BrowserUIUtils.jsm"
+  "BrowserUtils",
+  "resource://gre/modules/BrowserUtils.jsm"
 );
 ChromeUtils.defineModuleGetter(
   this,
@@ -367,7 +367,7 @@ class ExtensionControlledPopup {
       );
     } else {
       description.appendChild(
-        BrowserUIUtils.getLocalizedFragment(doc, message, addonDetails)
+        BrowserUtils.getLocalizedFragment(doc, message, addonDetails)
       );
     }
 
diff --git a/browser/components/extensions/parent/ext-tabs.js b/browser/components/extensions/parent/ext-tabs.js
index e05522d4e110..c88d35dc516e 100644
--- a/browser/components/extensions/parent/ext-tabs.js
+++ b/browser/components/extensions/parent/ext-tabs.js
@@ -8,8 +8,8 @@
 
 ChromeUtils.defineModuleGetter(
   this,
-  "BrowserUIUtils",
-  "resource:///modules/BrowserUIUtils.jsm"
+  "BrowserUtils",
+  "resource://gre/modules/BrowserUtils.jsm"
 );
 ChromeUtils.defineModuleGetter(
   this,
@@ -64,7 +64,7 @@ XPCOMUtils.defineLazyGetter(this, "tabHidePopup", () => {
     getLocalizedDescription: (doc, message, addonDetails) => {
       let image = doc.createXULElement("image");
       image.setAttribute("class", "extension-controlled-icon alltabs-icon");
-      return BrowserUIUtils.getLocalizedFragment(
+      return BrowserUtils.getLocalizedFragment(
         doc,
         message,
         addonDetails,
diff --git a/browser/components/originattributes/test/browser/browser_favicon_firstParty.js b/browser/components/originattributes/test/browser/browser_favicon_firstParty.js
index cd9867eebee6..a6ec99e0d722 100644
--- a/browser/components/originattributes/test/browser/browser_favicon_firstParty.js
+++ b/browser/components/originattributes/test/browser/browser_favicon_firstParty.js
@@ -42,6 +42,8 @@ const ICON_DATA =
   "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACAAAAAgCAYAAABzenr0AAABH0lEQVRYw2P8////f4YBBEwMAwxGHcBCUMX/91DGOSj/BpT/DkpzQChGBSjfBErLQsVZhmoI/L8LpRdD6X1QietQGhYy7FB5aAgwmkLpBKi4BZTPMThDgBGjHIDF+f9mKD0fKvGBRKNdoF7sgPL1saaJwZgGDkJ9vpZMn8PAHqg5G9FyifBgD4H/W9HyOWrU/f+DIzHhkoeZxxgzZEIAVtJ9RxX+Q6DAxCmP3byhXxkxshAs5odqbcioAY3UC1CBLyTGOTqAmsfAOWRCwBvqxV0oIUB2OQAzDy3/D+a6wB7q8mCU2vD/nw94GziYIQOtDRn9oXz+IZMGBKGMbCjNh9Ii+v8HR4uIAUeLiEEbb9twELaIRlqrmHG0bzjiHQAA1LVfww8jwM4AAAAASUVORK5CYII=";
 
 let systemPrincipal = Services.scriptSecurityManager.getSystemPrincipal();
+let makeURI = ChromeUtils.import("resource://gre/modules/BrowserUtils.jsm", {})
+  .BrowserUtils.makeURI;
 
 function clearAllImageCaches() {
   let tools = SpecialPowers.Cc["@mozilla.org/image/tools;1"].getService(
@@ -242,8 +244,8 @@ function assertIconIsData(item) {
 }
 
 async function doTest(aTestPage, aExpectedCookies, aFaviconURL) {
-  let firstPageURI = Services.io.newURI(TEST_SITE_ONE + aTestPage);
-  let secondPageURI = Services.io.newURI(TEST_SITE_TWO + aTestPage);
+  let firstPageURI = makeURI(TEST_SITE_ONE + aTestPage);
+  let secondPageURI = makeURI(TEST_SITE_TWO + aTestPage);
 
   // Start to observe the event of that favicon has been fully loaded.
   let promiseFaviconLoaded = waitOnFaviconLoaded(aFaviconURL);
diff --git a/browser/components/pocket/content/Pocket.jsm b/browser/components/pocket/content/Pocket.jsm
index de4d4958f7be..5b8c4a1c492f 100644
--- a/browser/components/pocket/content/Pocket.jsm
+++ b/browser/components/pocket/content/Pocket.jsm
@@ -10,8 +10,8 @@ const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
 
 ChromeUtils.defineModuleGetter(
   this,
-  "BrowserUIUtils",
-  "resource:///modules/BrowserUIUtils.jsm"
+  "BrowserUtils",
+  "resource://gre/modules/BrowserUtils.jsm"
 );
 
 var Pocket = {
@@ -46,7 +46,7 @@ var Pocket = {
 
     let libraryButton = document.getElementById("library-button");
     if (libraryButton) {
-      BrowserUIUtils.setToolbarButtonHeightProperty(libraryButton);
+      BrowserUtils.setToolbarButtonHeightProperty(libraryButton);
     }
 
     let urlToSave = Pocket._urlToSave;
diff --git a/browser/components/pocket/content/SaveToPocket.jsm b/browser/components/pocket/content/SaveToPocket.jsm
index 09e4aed67019..efb944fd38c0 100644
--- a/browser/components/pocket/content/SaveToPocket.jsm
+++ b/browser/components/pocket/content/SaveToPocket.jsm
@@ -11,8 +11,8 @@ const { XPCOMUtils } = ChromeUtils.import(
 const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
 ChromeUtils.defineModuleGetter(
   this,
-  "BrowserUIUtils",
-  "resource:///modules/BrowserUIUtils.jsm"
+  "BrowserUtils",
+  "resource://gre/modules/BrowserUtils.jsm"
 );
 ChromeUtils.defineModuleGetter(
   this,
@@ -76,7 +76,7 @@ var PocketPageAction = {
               return;
             }
 
-            BrowserUIUtils.setToolbarButtonHeightProperty(urlbarNode);
+            BrowserUtils.setToolbarButtonHeightProperty(urlbarNode);
 
             PocketPageAction.urlbarNode = urlbarNode;
             PocketPageAction.urlbarNode.setAttribute("open", "true");
diff --git a/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_favicon.js b/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_favicon.js
index b455a60fab5d..c0e671ce34ed 100644
--- a/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_favicon.js
+++ b/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_favicon.js
@@ -15,6 +15,8 @@ const FAVICON_URI = TEST_SITE + TEST_DIRECTORY + "file_favicon.png";
 const FAVICON_CACHE_URI = TEST_CACHE_SITE + TEST_DIRECTORY + "file_favicon.png";
 
 let systemPrincipal = Services.scriptSecurityManager.getSystemPrincipal();
+let makeURI = ChromeUtils.import("resource://gre/modules/BrowserUtils.jsm", {})
+  .BrowserUtils.makeURI;
 
 function clearAllImageCaches() {
   let tools = SpecialPowers.Cc["@mozilla.org/image/tools;1"].getService(
@@ -203,7 +205,7 @@ add_task(async function test_favicon_privateBrowsing() {
   let privateWindow = await BrowserTestUtils.openNewBrowserWindow({
     private: true,
   });
-  let pageURI = Services.io.newURI(TEST_PAGE);
+  let pageURI = makeURI(TEST_PAGE);
 
   // Generate two random cookies for non-private window and private window
   // respectively.
diff --git a/browser/components/sessionstore/test/browser_522545.js b/browser/components/sessionstore/test/browser_522545.js
index 3761b160ec0d..9955eb75875d 100644
--- a/browser/components/sessionstore/test/browser_522545.js
+++ b/browser/components/sessionstore/test/browser_522545.js
@@ -396,7 +396,7 @@ function test() {
       );
       is(
         gURLBar.value,
-        BrowserUIUtils.trimURL("http://example.com/"),
+        BrowserUtils.trimURL("http://example.com/"),
         "Address bar's value set after loading URI"
       );
       runNextTest();
diff --git a/browser/components/urlbar/UrlbarInput.jsm b/browser/components/urlbar/UrlbarInput.jsm
index 488af5a64428..ba414758c67f 100644
--- a/browser/components/urlbar/UrlbarInput.jsm
+++ b/browser/components/urlbar/UrlbarInput.jsm
@@ -13,7 +13,7 @@ const { XPCOMUtils } = ChromeUtils.import(
 XPCOMUtils.defineLazyModuleGetters(this, {
   AppConstants: "resource://gre/modules/AppConstants.jsm",
   BrowserSearchTelemetry: "resource:///modules/BrowserSearchTelemetry.jsm",
-  BrowserUIUtils: "resource:///modules/BrowserUIUtils.jsm",
+  BrowserUtils: "resource://gre/modules/BrowserUtils.jsm",
   ExtensionSearchHandler: "resource://gre/modules/ExtensionSearchHandler.jsm",
   ObjectUtils: "resource://gre/modules/ObjectUtils.jsm",
   PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.jsm",
@@ -330,7 +330,7 @@ class UrlbarInput {
       // only if there's no opener (bug 370555).
       if (
         this.window.isInitialPage(uri) &&
-        BrowserUIUtils.checkEmptyPageOrigin(
+        BrowserUtils.checkEmptyPageOrigin(
           this.window.gBrowser.selectedBrowser,
           uri
         )
@@ -349,7 +349,7 @@ class UrlbarInput {
         !this.window.isBlankPageURL(uri.spec) || uri.schemeIs("moz-extension");
     } else if (
       this.window.isInitialPage(value) &&
-      BrowserUIUtils.checkEmptyPageOrigin(this.window.gBrowser.selectedBrowser)
+      BrowserUtils.checkEmptyPageOrigin(this.window.gBrowser.selectedBrowser)
     ) {
       value = "";
       valid = true;
@@ -1076,10 +1076,10 @@ class UrlbarInput {
     if (
       result.type == UrlbarUtils.RESULT_TYPE.URL &&
       UrlbarPrefs.get("trimURLs") &&
-      result.payload.url.startsWith(BrowserUIUtils.trimURLProtocol)
+      result.payload.url.startsWith(BrowserUtils.trimURLProtocol)
     ) {
       let fixupInfo = this._getURIFixupInfo(
-        BrowserUIUtils.trimURL(result.payload.url)
+        BrowserUtils.trimURL(result.payload.url)
       );
       if (fixupInfo?.keywordAsSent) {
         allowTrim = false;
@@ -2089,12 +2089,12 @@ class UrlbarInput {
     // url. First check for a trimmed value.
 
     if (
-      !selectedVal.startsWith(BrowserUIUtils.trimURLProtocol) &&
+      !selectedVal.startsWith(BrowserUtils.trimURLProtocol) &&
       // Note _trimValue may also trim a trailing slash, thus we can't just do
       // a straight string compare to tell if the protocol was trimmed.
       !displaySpec.startsWith(this._trimValue(displaySpec))
     ) {
-      selectedVal = BrowserUIUtils.trimURLProtocol + selectedVal;
+      selectedVal = BrowserUtils.trimURLProtocol + selectedVal;
     }
 
     return selectedVal;
@@ -2176,7 +2176,7 @@ class UrlbarInput {
    *   The trimmed string
    */
   _trimValue(val) {
-    return UrlbarPrefs.get("trimURLs") ? BrowserUIUtils.trimURL(val) : val;
+    return UrlbarPrefs.get("trimURLs") ? BrowserUtils.trimURL(val) : val;
   }
 
   /**
@@ -3257,11 +3257,10 @@ function getDroppableData(event) {
     }
 
     try {
-      // If this throws, checkLoadURStrWithPrincipal would also throw,
-      // as that's what it does with things that don't pass the IO
-      // service's newURI constructor without fixup. It's conceivable we
-      // may want to relax this check in the future (so e.g. www.foo.com
-      // gets fixed up), but not right now.
+      // If this throws, urlSecurityCheck would also throw, as that's what it
+      // does with things that don't pass the IO service's newURI constructor
+      // without fixup. It's conceivable we may want to relax this check in
+      // the future (so e.g. www.foo.com gets fixed up), but not right now.
       let url = new URL(href);
       // If we succeed, try to pass security checks. If this works, return the
       // URL object. If the *security checks* fail, return null.
@@ -3269,9 +3268,9 @@ function getDroppableData(event) {
         let principal = Services.droppedLinkHandler.getTriggeringPrincipal(
           event
         );
-        Services.scriptSecurityManager.checkLoadURIStrWithPrincipal(
+        BrowserUtils.urlSecurityCheck(
+          url,
           principal,
-          url.href,
           Ci.nsIScriptSecurityManager.DISALLOW_INHERIT_PRINCIPAL
         );
         return url;
diff --git a/browser/components/urlbar/UrlbarResult.jsm b/browser/components/urlbar/UrlbarResult.jsm
index 5dd2f5a20392..fe333f74426f 100644
--- a/browser/components/urlbar/UrlbarResult.jsm
+++ b/browser/components/urlbar/UrlbarResult.jsm
@@ -18,7 +18,7 @@ const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
 );
 XPCOMUtils.defineLazyModuleGetters(this, {
-  BrowserUIUtils: "resource:///modules/BrowserUIUtils.jsm",
+  BrowserUtils: "resource://gre/modules/BrowserUtils.jsm",
   JsonSchemaValidator:
     "resource://gre/modules/components-utils/JsonSchemaValidator.jsm",
   Services: "resource://gre/modules/Services.jsm",
@@ -226,7 +226,7 @@ class UrlbarResult {
       payloadInfo.displayUrl = [...payloadInfo.url];
       let url = payloadInfo.displayUrl[0];
       if (url && UrlbarPrefs.get("trimURLs")) {
-        url = BrowserUIUtils.removeSingleTrailingSlashFromURL(url);
+        url = BrowserUtils.removeSingleTrailingSlashFromURL(url);
         if (url.startsWith("https://")) {
           url = url.substring(8);
           if (url.startsWith("www.")) {
diff --git a/browser/components/urlbar/UrlbarUtils.jsm b/browser/components/urlbar/UrlbarUtils.jsm
index 1b6ac525fa39..8ad5e3e28dab 100644
--- a/browser/components/urlbar/UrlbarUtils.jsm
+++ b/browser/components/urlbar/UrlbarUtils.jsm
@@ -21,9 +21,9 @@ const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
 );
 XPCOMUtils.defineLazyModuleGetters(this, {
+  BrowserUtils: "resource://gre/modules/BrowserUtils.jsm",
   BrowserWindowTracker: "resource:///modules/BrowserWindowTracker.jsm",
   FormHistory: "resource://gre/modules/FormHistory.jsm",
-  KeywordUtils: "resource://gre/modules/KeywordUtils.jsm",
   Log: "resource://gre/modules/Log.jsm",
   PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.jsm",
   PlacesUIUtils: "resource:///modules/PlacesUIUtils.jsm",
@@ -308,7 +308,7 @@ var UrlbarUtils = {
     }
 
     try {
-      [url, postData] = await KeywordUtils.parseUrlAndPostData(
+      [url, postData] = await BrowserUtils.parseUrlAndPostData(
         entry.url.href,
         entry.postData,
         param
diff --git a/browser/components/urlbar/tests/UrlbarTestUtils.jsm b/browser/components/urlbar/tests/UrlbarTestUtils.jsm
index c4c1384f03a8..2150b5364ae2 100644
--- a/browser/components/urlbar/tests/UrlbarTestUtils.jsm
+++ b/browser/components/urlbar/tests/UrlbarTestUtils.jsm
@@ -13,7 +13,7 @@ XPCOMUtils.defineLazyModuleGetters(this, {
   AddonTestUtils: "resource://testing-common/AddonTestUtils.jsm",
   AppConstants: "resource://gre/modules/AppConstants.jsm",
   BrowserTestUtils: "resource://testing-common/BrowserTestUtils.jsm",
-  BrowserUIUtils: "resource:///modules/BrowserUIUtils.jsm",
+  BrowserUtils: "resource://gre/modules/BrowserUtils.jsm",
   BrowserWindowTracker: "resource:///modules/BrowserWindowTracker.jsm",
   FormHistoryTestUtils: "resource://testing-common/FormHistoryTestUtils.jsm",
   PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.jsm",
@@ -113,7 +113,7 @@ var UrlbarTestUtils = {
     window.gURLBar.inputField.focus();
     // Using the value setter in some cases may trim and fetch unexpected
     // results, then pick an alternate path.
-    if (UrlbarPrefs.get("trimURLs") && value != BrowserUIUtils.trimURL(value)) {
+    if (UrlbarPrefs.get("trimURLs") && value != BrowserUtils.trimURL(value)) {
       window.gURLBar.inputField.value = value;
       fireInputEvent = true;
     } else {
diff --git a/browser/components/urlbar/tests/browser/browser_UrlbarInput_trimURLs.js b/browser/components/urlbar/tests/browser/browser_UrlbarInput_trimURLs.js
index bd22255bdec4..3c1f3ea8e4d9 100644
--- a/browser/components/urlbar/tests/browser/browser_UrlbarInput_trimURLs.js
+++ b/browser/components/urlbar/tests/browser/browser_UrlbarInput_trimURLs.js
@@ -102,7 +102,7 @@ function testVal(originalValue, targetValue) {
   gURLBar.value = originalValue;
   gURLBar.valueIsTyped = false;
   let trimmedValue = UrlbarPrefs.get("trimURLs")
-    ? BrowserUIUtils.trimURL(originalValue)
+    ? BrowserUtils.trimURL(originalValue)
     : originalValue;
   Assert.equal(gURLBar.value, trimmedValue, "url bar value set");
   // Now focus the urlbar and check the inputField value is properly set.
diff --git a/browser/components/urlbar/tests/browser/browser_edit_invalid_url.js b/browser/components/urlbar/tests/browser/browser_edit_invalid_url.js
index a74196a129eb..bbebc0f94066 100644
--- a/browser/components/urlbar/tests/browser/browser_edit_invalid_url.js
+++ b/browser/components/urlbar/tests/browser/browser_edit_invalid_url.js
@@ -5,7 +5,7 @@
 // modifies the selected url, or just closes the results pane, we do a visit
 // rather than searching for the trimmed string.
 
-const url = BrowserUIUtils.trimURLProtocol + "invalid.somehost/mytest";
+const url = BrowserUtils.trimURLProtocol + "invalid.somehost/mytest";
 
 add_task(async function setup() {
   await SpecialPowers.pushPrefEnv({
diff --git a/browser/components/urlbar/tests/browser/browser_stop.js b/browser/components/urlbar/tests/browser/browser_stop.js
index db7f04fded03..1bc011a31c10 100644
--- a/browser/components/urlbar/tests/browser/browser_stop.js
+++ b/browser/components/urlbar/tests/browser/browser_stop.js
@@ -16,14 +16,14 @@ add_task(async function() {
   await BrowserTestUtils.browserLoaded(gBrowser.selectedBrowser);
   is(
     gURLBar.value,
-    BrowserUIUtils.trimURL(goodURL),
+    BrowserUtils.trimURL(goodURL),
     "location bar reflects loaded page"
   );
 
   await typeAndSubmitAndStop(badURL);
   is(
     gURLBar.value,
-    BrowserUIUtils.trimURL(goodURL),
+    BrowserUtils.trimURL(goodURL),
     "location bar reflects loaded page after stop()"
   );
   gBrowser.removeCurrentTab();
@@ -34,7 +34,7 @@ add_task(async function() {
   await typeAndSubmitAndStop(badURL);
   is(
     gURLBar.value,
-    BrowserUIUtils.trimURL(badURL),
+    BrowserUtils.trimURL(badURL),
     "location bar reflects stopped page in an empty tab"
   );
   gBrowser.removeCurrentTab();
diff --git a/browser/components/urlbar/tests/browser/browser_valueOnTabSwitch.js b/browser/components/urlbar/tests/browser/browser_valueOnTabSwitch.js
index c8d9c3521f53..d1053dfc8e32 100644
--- a/browser/components/urlbar/tests/browser/browser_valueOnTabSwitch.js
+++ b/browser/components/urlbar/tests/browser/browser_valueOnTabSwitch.js
@@ -51,7 +51,7 @@ add_task(async function() {
   BrowserTestUtils.loadURI(partialURLTab.linkedBrowser, testURL);
   await Promise.all([loaded1, loaded2, loaded3]);
 
-  testURL = BrowserUIUtils.trimURL(testURL);
+  testURL = BrowserUtils.trimURL(testURL);
   testPartialURL = testURL.substr(0, testURL.length - charsToDelete);
 
   function cleanUp() {
diff --git a/browser/modules/BrowserUIUtils.jsm b/browser/modules/BrowserUIUtils.jsm
deleted file mode 100644
index 3f14c2eb0fbe..000000000000
--- a/browser/modules/BrowserUIUtils.jsm
+++ /dev/null
@@ -1,204 +0,0 @@
-/* -*- mode: js; indent-tabs-mode: nil; js-indent-level: 2 -*- */
-/* 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";
-
-var EXPORTED_SYMBOLS = ["BrowserUIUtils"];
-
-var BrowserUIUtils = {
-  /**
-   * Check whether a page can be considered as 'empty', that its URI
-   * reflects its origin, and that if it's loaded in a tab, that tab
-   * could be considered 'empty' (e.g. like the result of opening
-   * a 'blank' new tab).
-   *
-   * We have to do more than just check the URI, because especially
-   * for things like about:blank, it is possible that the opener or
-   * some other page has control over the contents of the page.
-   *
-   * @param {Browser} browser
-   *        The browser whose page we're checking.
-   * @param {nsIURI} [uri]
-   *        The URI against which we're checking (the browser's currentURI
-   *        if omitted).
-   *
-   * @return {boolean} false if the page was opened by or is controlled by
-   *         arbitrary web content, unless that content corresponds with the URI.
-   *         true if the page is blank and controlled by a principal matching
-   *         that URI (or the system principal if the principal has no URI)
-   */
-  checkEmptyPageOrigin(browser, uri = browser.currentURI) {
-    // If another page opened this page with e.g. window.open, this page might
-    // be controlled by its opener.
-    if (browser.hasContentOpener) {
-      return false;
-    }
-    let contentPrincipal = browser.contentPrincipal;
-    // Not all principals have URIs...
-    // There are two special-cases involving about:blank. One is where
-    // the user has manually loaded it and it got created with a null
-    // principal. The other involves the case where we load
-    // some other empty page in a browser and the current page is the
-    // initial about:blank page (which has that as its principal, not
-    // just URI in which case it could be web-based). Especially in
-    // e10s, we need to tackle that case specifically to avoid race
-    // conditions when updating the URL bar.
-    //
-    // Note that we check the documentURI here, since the currentURI on
-    // the browser might have been set by SessionStore in order to
-    // support switch-to-tab without having actually loaded the content
-    // yet.
-    let uriToCheck = browser.documentURI || uri;
-    if (
-      (uriToCheck.spec == "about:blank" && contentPrincipal.isNullPrincipal) ||
-      contentPrincipal.spec == "about:blank"
-    ) {
-      return true;
-    }
-    if (contentPrincipal.isContentPrincipal) {
-      return contentPrincipal.equalsURI(uri);
-    }
-    // ... so for those that don't have them, enforce that the page has the
-    // system principal (this matches e.g. on about:newtab).
-    return contentPrincipal.isSystemPrincipal;
-  },
-
-  /**
-   * Sets the --toolbarbutton-button-height CSS property on the closest
-   * toolbar to the provided element. Useful if you need to vertically
-   * center a position:absolute element within a toolbar that uses
-   * -moz-pack-align:stretch, and thus a height which is dependant on
-   * the font-size.
-   *
-   * @param element An element within the toolbar whose height is desired.
-   */
-  async setToolbarButtonHeightProperty(element) {
-    let window = element.ownerGlobal;
-    let dwu = window.windowUtils;
-    let toolbarItem = element;
-    let urlBarContainer = element.closest("#urlbar-container");
-    if (urlBarContainer) {
-      // The stop-reload-button, which is contained in #urlbar-container,
-      // needs to use #urlbar-container to calculate the bounds.
-      toolbarItem = urlBarContainer;
-    }
-    if (!toolbarItem) {
-      return;
-    }
-    let bounds = dwu.getBoundsWithoutFlushing(toolbarItem);
-    if (!bounds.height) {
-      await window.promiseDocumentFlushed(() => {
-        bounds = dwu.getBoundsWithoutFlushing(toolbarItem);
-      });
-    }
-    if (bounds.height) {
-      toolbarItem.style.setProperty(
-        "--toolbarbutton-height",
-        bounds.height + "px"
-      );
-    }
-  },
-
-  /**
-   * Generate a document fragment for a localized string that has DOM
-   * node replacements. This avoids using getFormattedString followed
-   * by assigning to innerHTML. Fluent can probably replace this when
-   * it is in use everywhere.
-   *
-   * @param {Document} doc
-   * @param {String}   msg
-   *                   The string to put replacements in. Fetch from
-   *                   a stringbundle using getString or GetStringFromName,
-   *                   or even an inserted dtd string.
-   * @param {Node|String} nodesOrStrings
-   *                   The replacement items. Can be a mix of Nodes
-   *                   and Strings. However, for correct behaviour, the
-   *                   number of items provided needs to exactly match
-   *                   the number of replacement strings in the l10n string.
-   * @returns {DocumentFragment}
-   *                   A document fragment. In the trivial case (no
-   *                   replacements), this will simply be a fragment with 1
-   *                   child, a text node containing the localized string.
-   */
-  getLocalizedFragment(doc, msg, ...nodesOrStrings) {
-    // Ensure replacement points are indexed:
-    for (let i = 1; i <= nodesOrStrings.length; i++) {
-      if (!msg.includes("%" + i + "$S")) {
-        msg = msg.replace(/%S/, "%" + i + "$S");
-      }
-    }
-    let numberOfInsertionPoints = msg.match(/%\d+\$S/g).length;
-    if (numberOfInsertionPoints != nodesOrStrings.length) {
-      Cu.reportError(
-        `Message has ${numberOfInsertionPoints} insertion points, ` +
-          `but got ${nodesOrStrings.length} replacement parameters!`
-      );
-    }
-
-    let fragment = doc.createDocumentFragment();
-    let parts = [msg];
-    let insertionPoint = 1;
-    for (let replacement of nodesOrStrings) {
-      let insertionString = "%" + insertionPoint++ + "$S";
-      let partIndex = parts.findIndex(
-        part => typeof part == "string" && part.includes(insertionString)
-      );
-      if (partIndex == -1) {
-        fragment.appendChild(doc.createTextNode(msg));
-        return fragment;
-      }
-
-      if (typeof replacement == "string") {
-        parts[partIndex] = parts[partIndex].replace(
-          insertionString,
-          replacement
-        );
-      } else {
-        let [firstBit, lastBit] = parts[partIndex].split(insertionString);
-        parts.splice(partIndex, 1, firstBit, replacement, lastBit);
-      }
-    }
-
-    // Put everything in a document fragment:
-    for (let part of parts) {
-      if (typeof part == "string") {
-        if (part) {
-          fragment.appendChild(doc.createTextNode(part));
-        }
-      } else {
-        fragment.appendChild(part);
-      }
-    }
-    return fragment;
-  },
-
-  removeSingleTrailingSlashFromURL(aURL) {
-    // remove single trailing slash for http/https/ftp URLs
-    return aURL.replace(/^((?:http|https|ftp):\/\/[^/]+)\/$/, "$1");
-  },
-
-  /**
-   * Returns a URL which has been trimmed by removing 'http://' and any
-   * trailing slash (in http/https/ftp urls).
-   * Note that a trimmed url may not load the same page as the original url, so
-   * before loading it, it must be passed through URIFixup, to check trimming
-   * doesn't change its destination. We don't run the URIFixup check here,
-   * because trimURL is in the page load path (see onLocationChange), so it
-   * must be fast and simple.
-   *
-   * @param {string} aURL The URL to trim.
-   * @returns {string} The trimmed string.
-   */
-  get trimURLProtocol() {
-    return "http://";
-  },
-  trimURL(aURL) {
-    let url = this.removeSingleTrailingSlashFromURL(aURL);
-    // Remove "http://" prefix.
-    return url.startsWith(this.trimURLProtocol)
-      ? url.substring(this.trimURLProtocol.length)
-      : url;
-  },
-};
diff --git a/browser/modules/BrowserUsageTelemetry.jsm b/browser/modules/BrowserUsageTelemetry.jsm
index e6e7a02dc925..3134c1fb1412 100644
--- a/browser/modules/BrowserUsageTelemetry.jsm
+++ b/browser/modules/BrowserUsageTelemetry.jsm
@@ -19,7 +19,7 @@ const { XPCOMUtils } = ChromeUtils.import(
 XPCOMUtils.defineLazyModuleGetters(this, {
   AppConstants: "resource://gre/modules/AppConstants.jsm",
   ClientID: "resource://gre/modules/ClientID.jsm",
-  BrowserTelemetryUtils: "resource://gre/modules/BrowserTelemetryUtils.jsm",
+  BrowserUtils: "resource://gre/modules/BrowserUtils.jsm",
   CustomizableUI: "resource:///modules/CustomizableUI.jsm",
   PageActions: "resource:///modules/PageActions.jsm",
   PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.jsm",
@@ -1208,7 +1208,7 @@ let BrowserUsageTelemetry = {
       }
 
       const { loadedTabCount } = getOpenTabsAndWinsCounts();
-      const siteOrigins = BrowserTelemetryUtils.computeSiteOriginCount(
+      const siteOrigins = BrowserUtils.computeSiteOriginCount(
         Services.wm.getEnumerator("navigator:browser"),
         false
       );
diff --git a/browser/modules/moz.build b/browser/modules/moz.build
index b069f1b641f7..06b809334b54 100644
--- a/browser/modules/moz.build
+++ b/browser/modules/moz.build
@@ -128,7 +128,6 @@ EXTRA_JS_MODULES += [
     "AboutNewTab.jsm",
     "AppUpdater.jsm",
     "AsyncTabSwitcher.jsm",
-    "BrowserUIUtils.jsm",
     "BrowserUsageTelemetry.jsm",
     "BrowserWindowTracker.jsm",
     "ContentCrashHandlers.jsm",
diff --git a/browser/themes/shared/toolbarbutton-icons.inc.css b/browser/themes/shared/toolbarbutton-icons.inc.css
index 691e52b40957..379e9e7be733 100644
--- a/browser/themes/shared/toolbarbutton-icons.inc.css
+++ b/browser/themes/shared/toolbarbutton-icons.inc.css
@@ -36,7 +36,7 @@ toolbar[brighttext] {
   animation-iteration-count: 1;
   list-style-image: none;
   /* Height must be equal to height of toolbarbutton padding-box. --toolbarbutton-height
-     is calculated and set during runtime by BrowserUIUtils.setToolbarButtonHeightProperty()
+     is calculated and set during runtime by BrowserUtils.setToolbarButtonHeightProperty()
      before the animation begins. */
   height: var(--toolbarbutton-height);
 }
diff --git a/caps/nsIScriptSecurityManager.idl b/caps/nsIScriptSecurityManager.idl
index e0497db33634..2cfb7b327165 100644
--- a/caps/nsIScriptSecurityManager.idl
+++ b/caps/nsIScriptSecurityManager.idl
@@ -113,20 +113,9 @@ interface nsIScriptSecurityManager : nsISupports
      *        will only appear in the browser console, not window-associated
      *        consoles like the web console.
      */
-    [binaryname(CheckLoadURIWithPrincipal)]
-    void checkLoadURIWithPrincipalXPCOM(in nsIPrincipal aPrincipal,
-                                        in nsIURI uri,
-                                        in unsigned long flags,
-                                        [optional] in unsigned long long innerWindowID);
-
-    /**
-     * Same as the above, but when called from JS, raises exceptions with more
-     * useful messages, including both the tested URI and the principal string.
-     */
-    [implicit_jscontext, binaryname(CheckLoadURIWithPrincipalFromJS)]
     void checkLoadURIWithPrincipal(in nsIPrincipal aPrincipal,
                                    in nsIURI uri,
-                                   [optional] in unsigned long flags,
+                                   in unsigned long flags,
                                    [optional] in unsigned long long innerWindowID);
 
     /**
@@ -138,19 +127,9 @@ interface nsIScriptSecurityManager : nsISupports
      * load as well); if any of the versions of this URI is not allowed, this
      * function will return error code NS_ERROR_DOM_BAD_URI.
      */
-    [binaryname(CheckLoadURIStrWithPrincipal)]
-    void checkLoadURIStrWithPrincipalXPCOM(in nsIPrincipal aPrincipal,
-                                           in AUTF8String uri,
-                                           in unsigned long flags);
-
-    /**
-     * Same as the above, but when called from JS, raises exceptions with more
-     * useful messages, including both the tested URI and the principal string.
-     */
-    [implicit_jscontext, binaryname(CheckLoadURIStrWithPrincipalFromJS)]
     void checkLoadURIStrWithPrincipal(in nsIPrincipal aPrincipal,
                                       in AUTF8String uri,
-                                      [optional] in unsigned long flags);
+                                      in unsigned long flags);
 
     /**
      * Returns true if the URI is from a domain that is allow-listed through
diff --git a/caps/nsScriptSecurityManager.cpp b/caps/nsScriptSecurityManager.cpp
index 22090b91c1c3..03d58446988b 100644
--- a/caps/nsScriptSecurityManager.cpp
+++ b/caps/nsScriptSecurityManager.cpp
@@ -57,11 +57,9 @@
 #include <stdint.h>
 #include "mozilla/dom/ContentChild.h"
 #include "mozilla/dom/ContentParent.h"
-#include "mozilla/dom/Exceptions.h"
 #include "mozilla/dom/nsCSPContext.h"
 #include "mozilla/dom/ScriptSettings.h"
 #include "mozilla/ClearOnShutdown.h"
-#include "mozilla/ResultExtensions.h"
 #include "mozilla/StaticPtr.h"
 #include "mozilla/dom/WorkerCommon.h"
 #include "mozilla/dom/WorkerPrivate.h"
@@ -1118,49 +1116,6 @@ nsScriptSecurityManager::CheckLoadURIStrWithPrincipal(
   return rv;
 }
 
-NS_IMETHODIMP
-nsScriptSecurityManager::CheckLoadURIWithPrincipalFromJS(nsIPrincipal* aPrincipal,
-                                                         nsIURI* aTargetURI,
-                                                         uint32_t aFlags,
-                                                         uint64_t aInnerWindowID,
-                                                         JSContext* aCx) {
-  NS_ENSURE_ARG_POINTER(aTargetURI);
-
-  nsresult rv = CheckLoadURIWithPrincipal(aPrincipal,
-                                          aTargetURI,
-                                          aFlags,
-                                          aInnerWindowID);
-  if (NS_FAILED(rv)) {
-    nsAutoCString uriStr;
-    Unused << aTargetURI->GetSpec(uriStr);
-
-    nsAutoCString message("Load of ");
-    message.Append(uriStr);
-
-    nsAutoCString principalStr;
-    Unused << aPrincipal->GetSpec(principalStr);
-    if (!principalStr.IsEmpty()) {
-      message.AppendPrintf(" from %s", principalStr.get());
-    }
-
-    message.Append(" denied");
-
-    dom::Throw(aCx, rv, message);
-  }
-
-  return rv;
-}
-
-NS_IMETHODIMP
-nsScriptSecurityManager::CheckLoadURIStrWithPrincipalFromJS(
-    nsIPrincipal* aPrincipal, const nsACString& aTargetURIStr,
-    uint32_t aFlags, JSContext* aCx) {
-  nsCOMPtr<nsIURI> targetURI;
-  MOZ_TRY(NS_NewURI(getter_AddRefs(targetURI), aTargetURIStr));
-
-  return CheckLoadURIWithPrincipalFromJS(aPrincipal, targetURI, aFlags, 0, aCx);
-}
-
 NS_IMETHODIMP
 nsScriptSecurityManager::InFileURIAllowlist(nsIURI* aUri, bool* aResult) {
   MOZ_ASSERT(aUri);
diff --git a/caps/tests/mochitest/browser_checkloaduri.js b/caps/tests/mochitest/browser_checkloaduri.js
index 3f114427335d..4607c802288e 100644
--- a/caps/tests/mochitest/browser_checkloaduri.js
+++ b/caps/tests/mochitest/browser_checkloaduri.js
@@ -254,7 +254,7 @@ function testURL(
   let threw = false;
   let targetURI;
   try {
-    targetURI = Services.io.newURI(target);
+    targetURI = makeURI(target);
   } catch (ex) {
     ok(
       !canCreate,
@@ -300,7 +300,7 @@ add_task(async function() {
     if (sourceString.startsWith("about:test-chrome-privs")) {
       source = ssm.getSystemPrincipal();
     } else {
-      source = ssm.createContentPrincipal(Services.io.newURI(sourceString), {});
+      source = ssm.createContentPrincipal(makeURI(sourceString), {});
     }
     for (let [
       target,
@@ -341,6 +341,10 @@ add_task(async function() {
       // eslint-disable-next-line no-shadow
       let baseFlags = ssm.STANDARD | ssm.DONT_REPORT_ERRORS;
       // eslint-disable-next-line no-unused-vars
+      let makeURI = ChromeUtils.import(
+        "resource://gre/modules/BrowserUtils.jsm",
+        {}
+      ).BrowserUtils.makeURI;
       let b = new content.Blob(["I am a blob"]);
       let contentBlobURI = content.URL.createObjectURL(b);
       let contentPrincipal = content.document.nodePrincipal;
diff --git a/dom/security/test/general/test_bug1277803.xhtml b/dom/security/test/general/test_bug1277803.xhtml
index 43afb1f1a355..482dd6b916ec 100644
--- a/dom/security/test/general/test_bug1277803.xhtml
+++ b/dom/security/test/general/test_bug1277803.xhtml
@@ -15,41 +15,46 @@
 
   <script type="application/javascript"><![CDATA[
     SimpleTest.requestCompleteLog();
+    let makeURI = ChromeUtils.import("resource://gre/modules/BrowserUtils.jsm", {}).BrowserUtils.makeURI;
 
     const BASE_URI = "http://mochi.test:8888/chrome/dom/security/test/general/";
     const FAVICON_URI = BASE_URI + "favicon_bug1277803.ico";
     const LOADING_URI = BASE_URI + "bug1277803.html";
     let testWindow; //will be used to trigger favicon load
 
-    const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
-
-    let expectedPrincipal = Services.scriptSecurityManager
-        .createContentPrincipal(Services.io.newURI(LOADING_URI), {});
-    let systemPrincipal = Services.scriptSecurityManager.getSystemPrincipal();
+    let securityManager = Cc["@mozilla.org/scriptsecuritymanager;1"].
+                          getService(Ci.nsIScriptSecurityManager);
+    let expectedPrincipal = securityManager.createContentPrincipal(makeURI(LOADING_URI), {});
+    let systemPrincipal = Cc["@mozilla.org/systemprincipal;1"].createInstance();
 
     function runTest() {
       // Register our observer to intercept favicon requests.
-      function observer(aSubject, aTopic, aData) {
-        // Make sure this is a favicon request.
-        let httpChannel = aSubject.QueryInterface(Ci.nsIHttpChannel);
-        if (FAVICON_URI != httpChannel.URI.spec) {
-          return;
+      let os = Cc["@mozilla.org/observer-service;1"].
+               getService(Ci.nsIObserverService);
+      let observer = {
+        observe: function(aSubject, aTopic, aData)
+        {
+          // Make sure this is a favicon request.
+          let httpChannel = aSubject.QueryInterface(Ci.nsIHttpChannel);
+          if (FAVICON_URI != httpChannel.URI.spec) {
+            return;
+          }
+
+          // Ensure the topic is the one we set an observer for.
+          is(aTopic, "http-on-modify-request", "Expected observer topic");
+
+          // Check for the correct loadingPrincipal, triggeringPrincipal.
+          let triggeringPrincipal = httpChannel.loadInfo.triggeringPrincipal;
+          let loadingPrincipal = httpChannel.loadInfo.loadingPrincipal;
+
+          ok(loadingPrincipal.equals(expectedPrincipal), "Should be loading with the expected principal.");
+          ok(triggeringPrincipal.equals(expectedPrincipal), "Should be triggered with the expected principal.");
+
+          os.removeObserver(this, "http-on-modify-request");
+          SimpleTest.finish();
         }
-
-        // Ensure the topic is the one we set an observer for.
-        is(aTopic, "http-on-modify-request", "Expected observer topic");
-
-        // Check for the correct loadingPrincipal, triggeringPrincipal.
-        let triggeringPrincipal = httpChannel.loadInfo.triggeringPrincipal;
-        let loadingPrincipal = httpChannel.loadInfo.loadingPrincipal;
-
-        ok(loadingPrincipal.equals(expectedPrincipal), "Should be loading with the expected principal.");
-        ok(triggeringPrincipal.equals(expectedPrincipal), "Should be triggered with the expected principal.");
-
-        Services.obs.removeObserver(this, "http-on-modify-request");
-        SimpleTest.finish();
       }
-      Services.obs.addObserver(observer, "http-on-modify-request");
+      os.addObserver(observer, "http-on-modify-request");
 
       // Now that the observer is set up, trigger a favicon load with navigation
       testWindow = window.open(LOADING_URI);
diff --git a/mobile/android/modules/geckoview/GeckoViewProgress.jsm b/mobile/android/modules/geckoview/GeckoViewProgress.jsm
index 17069dbe657f..23652971ca69 100644
--- a/mobile/android/modules/geckoview/GeckoViewProgress.jsm
+++ b/mobile/android/modules/geckoview/GeckoViewProgress.jsm
@@ -29,7 +29,7 @@ XPCOMUtils.defineLazyServiceGetter(
 );
 
 XPCOMUtils.defineLazyModuleGetters(this, {
-  BrowserTelemetryUtils: "resource://gre/modules/BrowserTelemetryUtils.jsm",
+  BrowserUtils: "resource://gre/modules/BrowserUtils.jsm",
   HistogramStopwatch: "resource://gre/modules/GeckoViewTelemetry.jsm",
 });
 
@@ -435,7 +435,7 @@ class StateTracker extends Tracker {
       success: aIsSuccess,
     });
 
-    BrowserTelemetryUtils.recordSiteOriginTelemetry(
+    BrowserUtils.recordSiteOriginTelemetry(
       Services.wm.getEnumerator("navigator:geckoview"),
       true
     );
diff --git a/toolkit/actors/AutoCompleteChild.jsm b/toolkit/actors/AutoCompleteChild.jsm
index a10dd9c0fe58..b860d10c21f0 100644
--- a/toolkit/actors/AutoCompleteChild.jsm
+++ b/toolkit/actors/AutoCompleteChild.jsm
@@ -11,8 +11,8 @@ const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
 
 ChromeUtils.defineModuleGetter(
   this,
-  "LayoutUtils",
-  "resource://gre/modules/LayoutUtils.jsm"
+  "BrowserUtils",
+  "resource://gre/modules/BrowserUtils.jsm"
 );
 
 ChromeUtils.defineModuleGetter(
@@ -136,7 +136,7 @@ class AutoCompleteChild extends JSWindowActorChild {
       return;
     }
 
-    let rect = LayoutUtils.getElementBoundingScreenRect(element);
+    let rect = BrowserUtils.getElementBoundingScreenRect(element);
     let window = element.ownerGlobal;
     let dir = window.getComputedStyle(element).direction;
     let results = this.getResultsFromController(input);
diff --git a/toolkit/actors/DateTimePickerChild.jsm b/toolkit/actors/DateTimePickerChild.jsm
index 7a3a7d7c6225..0bfce7f0a7d6 100644
--- a/toolkit/actors/DateTimePickerChild.jsm
+++ b/toolkit/actors/DateTimePickerChild.jsm
@@ -5,8 +5,8 @@
 const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
 ChromeUtils.defineModuleGetter(
   this,
-  "LayoutUtils",
-  "resource://gre/modules/LayoutUtils.jsm"
+  "BrowserUtils",
+  "resource://gre/modules/BrowserUtils.jsm"
 );
 
 var EXPORTED_SYMBOLS = ["DateTimePickerChild"];
@@ -78,7 +78,7 @@ class DateTimePickerChild extends JSWindowActorChild {
    * relative to the left/top of the content area.
    */
   getBoundingContentRect(aElement) {
-    return LayoutUtils.getElementBoundingScreenRect(aElement);
+    return BrowserUtils.getElementBoundingScreenRect(aElement);
   }
 
   getTimePickerPref() {
diff --git a/toolkit/actors/SelectChild.jsm b/toolkit/actors/SelectChild.jsm
index 5b96a02a0e8b..54a60d178b87 100644
--- a/toolkit/actors/SelectChild.jsm
+++ b/toolkit/actors/SelectChild.jsm
@@ -12,8 +12,8 @@ const { XPCOMUtils } = ChromeUtils.import(
 
 ChromeUtils.defineModuleGetter(
   this,
-  "LayoutUtils",
-  "resource://gre/modules/LayoutUtils.jsm"
+  "BrowserUtils",
+  "resource://gre/modules/BrowserUtils.jsm"
 );
 ChromeUtils.defineModuleGetter(
   this,
@@ -173,7 +173,7 @@ SelectContentHelper.prototype = {
   },
 
   _getBoundingContentRect() {
-    return LayoutUtils.getElementBoundingScreenRect(this.element);
+    return BrowserUtils.getElementBoundingScreenRect(this.element);
   },
 
   _buildOptionList() {
diff --git a/toolkit/components/places/UnifiedComplete.jsm b/toolkit/components/places/UnifiedComplete.jsm
index b35356053d38..fe3b57a4d750 100644
--- a/toolkit/components/places/UnifiedComplete.jsm
+++ b/toolkit/components/places/UnifiedComplete.jsm
@@ -142,7 +142,7 @@ XPCOMUtils.defineLazyGlobalGetters(this, ["fetch"]);
 
 XPCOMUtils.defineLazyModuleGetters(this, {
   AboutPagesUtils: "resource://gre/modules/AboutPagesUtils.jsm",
-  KeywordUtils: "resource://gre/modules/KeywordUtils.jsm",
+  BrowserUtils: "resource://gre/modules/BrowserUtils.jsm",
   ObjectUtils: "resource://gre/modules/ObjectUtils.jsm",
   PlacesRemoteTabsAutocompleteProvider:
     "resource://gre/modules/PlacesRemoteTabsAutocompleteProvider.jsm",
@@ -1041,7 +1041,7 @@ Search.prototype = {
     let url = null;
     let postData = null;
     try {
-      [url, postData] = await KeywordUtils.parseUrlAndPostData(
+      [url, postData] = await BrowserUtils.parseUrlAndPostData(
         entry.url.href,
         entry.postData,
         searchString
diff --git a/toolkit/components/prompts/src/Prompter.jsm b/toolkit/components/prompts/src/Prompter.jsm
index 5ecc818eb8c8..765783ac8a0b 100644
--- a/toolkit/components/prompts/src/Prompter.jsm
+++ b/toolkit/components/prompts/src/Prompter.jsm
@@ -8,6 +8,9 @@ const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
 );
 const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
+const { objectToPropBag } = ChromeUtils.import(
+  "resource://gre/modules/BrowserUtils.jsm"
+).BrowserUtils;
 // This is redefined below, for strange and unfortunate reasons.
 var { PromptUtils } = ChromeUtils.import(
   "resource://gre/modules/SharedPromptUtils.jsm"
@@ -1201,7 +1204,7 @@ class ModalPrompter {
     if (!(taskResult instanceof Object)) {
       throw new Error("task must return object");
     }
-    return PromptUtils.objectToPropBag(taskResult);
+    return objectToPropBag(taskResult);
   }
 
   /*
diff --git a/toolkit/components/prompts/test/prompt_common.js b/toolkit/components/prompts/test/prompt_common.js
index 3e390d10a93b..909afc294607 100644
--- a/toolkit/components/prompts/test/prompt_common.js
+++ b/toolkit/components/prompts/test/prompt_common.js
@@ -1,20 +1,8 @@
 const { Cc, Ci, Cu: ChromeUtils } = SpecialPowers;
 
-/**
- * Converts a property bag to object.
- * @param {nsIPropertyBag} bag - The property bag to convert
- * @returns {Object} - The object representation of the nsIPropertyBag
- */
-function propBagToObject(bag) {
-  if (!(bag instanceof Ci.nsIPropertyBag)) {
-    throw new TypeError("Not a property bag");
-  }
-  let result = {};
-  for (let { name, value } of bag.enumerator) {
-    result[name] = value;
-  }
-  return result;
-}
+const { propBagToObject } = ChromeUtils.import(
+  "resource://gre/modules/BrowserUtils.jsm"
+).BrowserUtils;
 
 var modalType;
 var tabSubDialogsEnabled = SpecialPowers.Services.prefs.getBoolPref(
diff --git a/toolkit/components/thumbnails/PageThumbUtils.jsm b/toolkit/components/thumbnails/PageThumbUtils.jsm
index 237bdb349749..521adf57b3df 100644
--- a/toolkit/components/thumbnails/PageThumbUtils.jsm
+++ b/toolkit/components/thumbnails/PageThumbUtils.jsm
@@ -344,7 +344,7 @@ var PageThumbUtils = {
   },
 
   shouldStoreContentThumbnail(aDocument, aDocShell) {
-    if (BrowserUtils.isFindbarVisible(aDocShell)) {
+    if (BrowserUtils.isToolbarVisible(aDocShell, "findbar")) {
       return false;
     }
 
diff --git a/toolkit/content/contentAreaUtils.js b/toolkit/content/contentAreaUtils.js
index 371e2b67fb67..71b44f84e078 100644
--- a/toolkit/content/contentAreaUtils.js
+++ b/toolkit/content/contentAreaUtils.js
@@ -31,24 +31,8 @@ var ContentAreaUtils = {
   },
 };
 
-function urlSecurityCheck(
-  aURL,
-  aPrincipal,
-  aFlags = Services.scriptSecurityManager
-) {
-  if (aURL instanceof Ci.nsIURI) {
-    Services.scriptSecurityManager.checkLoadURIWithPrincipal(
-      aPrincipal,
-      aURL,
-      aFlags
-    );
-  } else {
-    Services.scriptSecurityManager.checkLoadURIStrWithPrincipal(
-      aPrincipal,
-      aURL,
-      aFlags
-    );
-  }
+function urlSecurityCheck(aURL, aPrincipal, aFlags) {
+  return BrowserUtils.urlSecurityCheck(aURL, aPrincipal, aFlags);
 }
 
 // Clientele: (Make sure you don't break any of these)
diff --git a/toolkit/modules/BrowserTelemetryUtils.jsm b/toolkit/modules/BrowserTelemetryUtils.jsm
deleted file mode 100644
index be794a753723..000000000000
--- a/toolkit/modules/BrowserTelemetryUtils.jsm
+++ /dev/null
@@ -1,199 +0,0 @@
-/* -*- mode: js; indent-tabs-mode: nil; js-indent-level: 2 -*- */
-/* 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";
-
-var EXPORTED_SYMBOLS = ["BrowserTelemetryUtils"];
-
-const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
-const { XPCOMUtils } = ChromeUtils.import(
-  "resource://gre/modules/XPCOMUtils.jsm"
-);
-
-// The maximum number of concurrently-loaded origins allowed in order to
-// qualify for the Fission rollout experiment.
-XPCOMUtils.defineLazyPreferenceGetter(
-  this,
-  "fissionExperimentMaxOrigins",
-  "fission.experiment.max-origins.origin-cap",
-  30
-);
-// The length of the sliding window during which a user must stay below
-// the max origin cap. If the last time a user passed the max origin cap
-// fell outside of this window, they will requalify for the experiment.
-XPCOMUtils.defineLazyPreferenceGetter(
-  this,
-  "fissionExperimentSlidingWindowMS",
-  "fission.experiment.max-origins.sliding-window-ms",
-  7 * 24 * 60 * 60 * 1000
-);
-// The pref holding the current qaualification state of the user. If
-// true, the user is currently qualified from the experiment.
-const FISSION_EXPERIMENT_PREF_QUALIFIED =
-  "fission.experiment.max-origins.qualified";
-XPCOMUtils.defineLazyPreferenceGetter(
-  this,
-  "fissionExperimentQualified",
-  FISSION_EXPERIMENT_PREF_QUALIFIED,
-  false
-);
-// The pref holding the timestamp of the last time we saw an origin
-// count below the cap while the user was not currently marked as
-// qualified.
-const FISSION_EXPERIMENT_PREF_LAST_QUALIFIED =
-  "fission.experiment.max-origins.last-qualified";
-XPCOMUtils.defineLazyPreferenceGetter(
-  this,
-  "fissionExperimentLastQualified",
-  FISSION_EXPERIMENT_PREF_LAST_QUALIFIED,
-  0
-);
-// The pref holding the timestamp of the last time we saw an origin
-// count exceeding the cap.
-const FISSION_EXPERIMENT_PREF_LAST_DISQUALIFIED =
-  "fission.experiment.max-origins.last-disqualified";
-XPCOMUtils.defineLazyPreferenceGetter(
-  this,
-  "fissionExperimentLastDisqualified",
-  FISSION_EXPERIMENT_PREF_LAST_DISQUALIFIED,
-  0
-);
-
-var BrowserTelemetryUtils = {
-  recordSiteOriginTelemetry(aWindows, aIsGeckoView) {
-    Services.tm.idleDispatchToMainThread(() => {
-      this._recordSiteOriginTelemetry(aWindows, aIsGeckoView);
-    });
-  },
-
-  computeSiteOriginCount(aWindows, aIsGeckoView) {
-    // Geckoview and Desktop work differently. On desktop, aBrowser objects
-    // holds an array of tabs which we can use to get the <browser> objects.
-    // In Geckoview, it is apps' responsibility to keep track of the tabs, so
-    // there isn't an easy way for us to get the tabs.
-    let tabs = [];
-    if (aIsGeckoView) {
-      // To get all active windows; Each tab has its own window
-      tabs = aWindows;
-    } else {
-      for (const win of aWindows) {
-        tabs = tabs.concat(win.gBrowser.tabs);
-      }
-    }
-
-    let topLevelBCs = [];
-
-    for (const tab of tabs) {
-      let browser;
-      if (aIsGeckoView) {
-        browser = tab.browser;
-      } else {
-        browser = tab.linkedBrowser;
-      }
-
-      if (browser.browsingContext) {
-        // This is the top level browsingContext
-        topLevelBCs.push(browser.browsingContext);
-      }
-    }
-
-    return CanonicalBrowsingContext.countSiteOrigins(topLevelBCs);
-  },
-
-  _recordSiteOriginTelemetry(aWindows, aIsGeckoView) {
-    let currentTime = Date.now();
-
-    // default is 5 minutes
-    if (!this.min_interval) {
-      this.min_interval = Services.prefs.getIntPref(
-        "telemetry.number_of_site_origin.min_interval",
-        300000
-      );
-    }
-
-    let originCount = this.computeSiteOriginCount(aWindows, aIsGeckoView);
-    let histogram = Services.telemetry.getHistogramById(
-      "FX_NUMBER_OF_UNIQUE_SITE_ORIGINS_ALL_TABS"
-    );
-
-    // Discard the first load because most of the time the first load only has 1
-    // tab and 1 window open, so it is useless to report it.
-    if (!this._lastRecordSiteOrigin) {
-      this._lastRecordSiteOrigin = currentTime;
-    } else if (currentTime >= this._lastRecordSiteOrigin + this.min_interval) {
-      this._lastRecordSiteOrigin = currentTime;
-
-      histogram.add(originCount);
-    }
-
-    // Update the Fission experiment qualification state based on the
-    // current origin count:
-
-    // If we don't already have a last disqualification timestamp, look
-    // through the existing histogram values, and use the existing
-    // maximum value as the initial count. This will prevent us from
-    // enrolling users in the experiment if they have a history of
-    // exceeding our origin cap.
-    if (!this._checkedInitialExperimentQualification) {
-      this._checkedInitialExperimentQualification = true;
-      if (
-        !Services.prefs.prefHasUserValue(
-          FISSION_EXPERIMENT_PREF_LAST_DISQUALIFIED
-        )
-      ) {
-        for (let [bucketStr, entryCount] of Object.entries(
-          histogram.snapshot().values
-        )) {
-          let bucket = Number(bucketStr);
-          if (bucket > originCount && entryCount > 0) {
-            originCount = bucket;
-          }
-        }
-        Services.prefs.setIntPref(FISSION_EXPERIMENT_PREF_LAST_DISQUALIFIED, 0);
-      }
-    }
-
-    let currentTimeSec = currentTime / 1000;
-    if (originCount < fissionExperimentMaxOrigins) {
-      let lastDisqualified = fissionExperimentLastDisqualified;
-      let lastQualified = fissionExperimentLastQualified;
-
-      // If the last time we saw a qualifying origin count was earlier
-      // than the last time we say a disqualifying count, update any
-      // existing last disqualified timestamp to just before now, on the
-      // basis that our origin count has probably just fallen below the
-      // cap.
-      if (lastDisqualified > 0 && lastQualified <= lastDisqualified) {
-        Services.prefs.setIntPref(
-          FISSION_EXPERIMENT_PREF_LAST_DISQUALIFIED,
-          currentTimeSec - 1
-        );
-      }
-
-      if (!fissionExperimentQualified) {
-        Services.prefs.setIntPref(
-          FISSION_EXPERIMENT_PREF_LAST_QUALIFIED,
-          currentTimeSec
-        );
-
-        // We have a qualifying origin count now. If the last time we were
-        // disqualified was prior to the start of our current sliding
-        // window, re-qualify the user.
-        if (
-          currentTimeSec - lastDisqualified >=
-          fissionExperimentSlidingWindowMS / 1000
-        ) {
-          Services.prefs.setBoolPref(FISSION_EXPERIMENT_PREF_QUALIFIED, true);
-        }
-      }
-    } else {
-      Services.prefs.setIntPref(
-        FISSION_EXPERIMENT_PREF_LAST_DISQUALIFIED,
-        currentTimeSec
-      );
-      Services.prefs.setBoolPref(FISSION_EXPERIMENT_PREF_QUALIFIED, false);
-    }
-  },
-};
diff --git a/toolkit/modules/BrowserUtils.jsm b/toolkit/modules/BrowserUtils.jsm
index db1ec513d16c..1020f9ca16d4 100644
--- a/toolkit/modules/BrowserUtils.jsm
+++ b/toolkit/modules/BrowserUtils.jsm
@@ -11,8 +11,196 @@ const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
 const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
 );
+ChromeUtils.defineModuleGetter(
+  this,
+  "PlacesUtils",
+  "resource://gre/modules/PlacesUtils.jsm"
+);
+
+// The maximum number of concurrently-loaded origins allowed in order to
+// qualify for the Fission rollout experiment.
+XPCOMUtils.defineLazyPreferenceGetter(
+  this,
+  "fissionExperimentMaxOrigins",
+  "fission.experiment.max-origins.origin-cap",
+  30
+);
+// The length of the sliding window during which a user must stay below
+// the max origin cap. If the last time a user passed the max origin cap
+// fell outside of this window, they will requalify for the experiment.
+XPCOMUtils.defineLazyPreferenceGetter(
+  this,
+  "fissionExperimentSlidingWindowMS",
+  "fission.experiment.max-origins.sliding-window-ms",
+  7 * 24 * 60 * 60 * 1000
+);
+// The pref holding the current qaualification state of the user. If
+// true, the user is currently qualified from the experiment.
+const FISSION_EXPERIMENT_PREF_QUALIFIED =
+  "fission.experiment.max-origins.qualified";
+XPCOMUtils.defineLazyPreferenceGetter(
+  this,
+  "fissionExperimentQualified",
+  FISSION_EXPERIMENT_PREF_QUALIFIED,
+  false
+);
+// The pref holding the timestamp of the last time we saw an origin
+// count below the cap while the user was not currently marked as
+// qualified.
+const FISSION_EXPERIMENT_PREF_LAST_QUALIFIED =
+  "fission.experiment.max-origins.last-qualified";
+XPCOMUtils.defineLazyPreferenceGetter(
+  this,
+  "fissionExperimentLastQualified",
+  FISSION_EXPERIMENT_PREF_LAST_QUALIFIED,
+  0
+);
+// The pref holding the timestamp of the last time we saw an origin
+// count exceeding the cap.
+const FISSION_EXPERIMENT_PREF_LAST_DISQUALIFIED =
+  "fission.experiment.max-origins.last-disqualified";
+XPCOMUtils.defineLazyPreferenceGetter(
+  this,
+  "fissionExperimentLastDisqualified",
+  FISSION_EXPERIMENT_PREF_LAST_DISQUALIFIED,
+  0
+);
 
 var BrowserUtils = {
+  /**
+   * Prints arguments separated by a space and appends a new line.
+   */
+  dumpLn(...args) {
+    for (let a of args) {
+      dump(a + " ");
+    }
+    dump("\n");
+  },
+
+  /**
+   * restartApplication: Restarts the application, keeping it in
+   * safe mode if it is already in safe mode.
+   */
+  restartApplication() {
+    let cancelQuit = Cc["@mozilla.org/supports-PRBool;1"].createInstance(
+      Ci.nsISupportsPRBool
+    );
+    Services.obs.notifyObservers(
+      cancelQuit,
+      "quit-application-requested",
+      "restart"
+    );
+    if (cancelQuit.data) {
+      // The quit request has been canceled.
+      return false;
+    }
+    // if already in safe mode restart in safe mode
+    if (Services.appinfo.inSafeMode) {
+      Services.startup.restartInSafeMode(
+        Ci.nsIAppStartup.eAttemptQuit | Ci.nsIAppStartup.eRestart
+      );
+      return undefined;
+    }
+    Services.startup.quit(
+      Ci.nsIAppStartup.eAttemptQuit | Ci.nsIAppStartup.eRestart
+    );
+    return undefined;
+  },
+
+  /**
+   * Check whether a page can be considered as 'empty', that its URI
+   * reflects its origin, and that if it's loaded in a tab, that tab
+   * could be considered 'empty' (e.g. like the result of opening
+   * a 'blank' new tab).
+   *
+   * We have to do more than just check the URI, because especially
+   * for things like about:blank, it is possible that the opener or
+   * some other page has control over the contents of the page.
+   *
+   * @param {Browser} browser
+   *        The browser whose page we're checking.
+   * @param {nsIURI} [uri]
+   *        The URI against which we're checking (the browser's currentURI
+   *        if omitted).
+   *
+   * @return {boolean} false if the page was opened by or is controlled by
+   *         arbitrary web content, unless that content corresponds with the URI.
+   *         true if the page is blank and controlled by a principal matching
+   *         that URI (or the system principal if the principal has no URI)
+   */
+  checkEmptyPageOrigin(browser, uri = browser.currentURI) {
+    // If another page opened this page with e.g. window.open, this page might
+    // be controlled by its opener.
+    if (browser.hasContentOpener) {
+      return false;
+    }
+    let contentPrincipal = browser.contentPrincipal;
+    // Not all principals have URIs...
+    // There are two special-cases involving about:blank. One is where
+    // the user has manually loaded it and it got created with a null
+    // principal. The other involves the case where we load
+    // some other empty page in a browser and the current page is the
+    // initial about:blank page (which has that as its principal, not
+    // just URI in which case it could be web-based). Especially in
+    // e10s, we need to tackle that case specifically to avoid race
+    // conditions when updating the URL bar.
+    //
+    // Note that we check the documentURI here, since the currentURI on
+    // the browser might have been set by SessionStore in order to
+    // support switch-to-tab without having actually loaded the content
+    // yet.
+    let uriToCheck = browser.documentURI || uri;
+    if (
+      (uriToCheck.spec == "about:blank" && contentPrincipal.isNullPrincipal) ||
+      contentPrincipal.spec == "about:blank"
+    ) {
+      return true;
+    }
+    if (contentPrincipal.isContentPrincipal) {
+      return contentPrincipal.equalsURI(uri);
+    }
+    // ... so for those that don't have them, enforce that the page has the
+    // system principal (this matches e.g. on about:newtab).
+    return contentPrincipal.isSystemPrincipal;
+  },
+
+  /**
+   * urlSecurityCheck: JavaScript wrapper for checkLoadURIWithPrincipal
+   * and checkLoadURIStrWithPrincipal.
+   * If |aPrincipal| is not allowed to link to |aURL|, this function throws with
+   * an error message.
+   *
+   * @param aURL
+   *        The URL a page has linked to. This could be passed either as a string
+   *        or as a nsIURI object.
+   * @param aPrincipal
+   *        The principal of the document from which aURL came.
+   * @param aFlags
+   *        Flags to be passed to checkLoadURIStr. If undefined,
+   *        nsIScriptSecurityManager.STANDARD will be passed.
+   */
+  urlSecurityCheck(aURL, aPrincipal, aFlags) {
+    var secMan = Services.scriptSecurityManager;
+    if (aFlags === undefined) {
+      aFlags = secMan.STANDARD;
+    }
+
+    try {
+      if (aURL instanceof Ci.nsIURI) {
+        secMan.checkLoadURIWithPrincipal(aPrincipal, aURL, aFlags);
+      } else {
+        secMan.checkLoadURIStrWithPrincipal(aPrincipal, aURL, aFlags);
+      }
+    } catch (e) {
+      let principalStr = "";
+      try {
+        principalStr = " from " + aPrincipal.spec;
+      } catch (e2) {}
+
+      throw new Error(`Load of ${aURL + principalStr} denied.`);
+    }
+  },
+
   /**
    * Return or create a principal with the content of one, and the originAttributes
    * of an existing principal (e.g. on a docshell, where the originAttributes ought
@@ -54,6 +242,102 @@ var BrowserUtils = {
     );
   },
 
+  /**
+   * Constructs a new URI, using nsIIOService.
+   * @param aURL The URI spec.
+   * @param aOriginCharset The charset of the URI.
+   * @param aBaseURI Base URI to resolve aURL, or null.
+   * @return an nsIURI object based on aURL.
+   *
+   * @deprecated Use Services.io.newURI directly instead.
+   */
+  makeURI(aURL, aOriginCharset, aBaseURI) {
+    return Services.io.newURI(aURL, aOriginCharset, aBaseURI);
+  },
+
+  /**
+   * @deprecated Use Services.io.newFileURI directly instead.
+   */
+  makeFileURI(aFile) {
+    return Services.io.newFileURI(aFile);
+  },
+
+  /**
+   * For a given DOM element, returns its position in "screen"
+   * coordinates. In a content process, the coordinates returned will
+   * be relative to the left/top of the tab. In the chrome process,
+   * the coordinates are relative to the user's screen.
+   */
+  getElementBoundingScreenRect(aElement) {
+    return this.getElementBoundingRect(aElement, true);
+  },
+
+  /**
+   * For a given DOM element, returns its position as an offset from the topmost
+   * window. In a content process, the coordinates returned will be relative to
+   * the left/top of the topmost content area. If aInScreenCoords is true,
+   * screen coordinates will be returned instead.
+   */
+  getElementBoundingRect(aElement, aInScreenCoords) {
+    let rect = aElement.getBoundingClientRect();
+    let win = aElement.ownerGlobal;
+
+    let x = rect.left;
+    let y = rect.top;
+
+    // We need to compensate for any iframes that might shift things
+    // over. We also need to compensate for zooming.
+    let parentFrame = win.frameElement;
+    while (parentFrame) {
+      win = parentFrame.ownerGlobal;
+      let cstyle = win.getComputedStyle(parentFrame);
+
+      let framerect = parentFrame.getBoundingClientRect();
+      x +=
+        framerect.left +
+        parseFloat(cstyle.borderLeftWidth) +
+        parseFloat(cstyle.paddingLeft);
+      y +=
+        framerect.top +
+        parseFloat(cstyle.borderTopWidth) +
+        parseFloat(cstyle.paddingTop);
+
+      parentFrame = win.frameElement;
+    }
+
+    rect = {
+      left: x,
+      top: y,
+      width: rect.width,
+      height: rect.height,
+    };
+    rect = win.windowUtils.transformRectLayoutToVisual(
+      rect.left,
+      rect.top,
+      rect.width,
+      rect.height
+    );
+
+    if (aInScreenCoords) {
+      rect = {
+        left: rect.left + win.mozInnerScreenX,
+        top: rect.top + win.mozInnerScreenY,
+        width: rect.width,
+        height: rect.height,
+      };
+    }
+
+    let fullZoom = win.windowUtils.fullZoom;
+    rect = {
+      left: rect.left * fullZoom,
+      top: rect.top * fullZoom,
+      width: rect.width * fullZoom,
+      height: rect.height * fullZoom,
+    };
+
+    return rect;
+  },
+
   onBeforeLinkTraversal(originalTarget, linkURI, linkNode, isAppTab) {
     // Don't modify non-default targets or targets that aren't in top-level app
     // tab docshells (isAppTab will be false for app tab subframes).
@@ -90,6 +374,35 @@ var BrowserUtils = {
     return "_blank";
   },
 
+  /**
+   * Map the plugin's name to a filtered version more suitable for UI.
+   *
+   * @param aName The full-length name string of the plugin.
+   * @return the simplified name string.
+   */
+  makeNicePluginName(aName) {
+    if (aName == "Shockwave Flash") {
+      return "Adobe Flash";
+    }
+    // Regex checks if aName begins with "Java" + non-letter char
+    if (/^Java\W/.exec(aName)) {
+      return "Java";
+    }
+
+    // Clean up the plugin name by stripping off parenthetical clauses,
+    // trailing version numbers or "plugin".
+    // EG, "Foo Bar (Linux) Plugin 1.23_02" --> "Foo Bar"
+    // Do this by first stripping the numbers, etc. off the end, and then
+    // removing "Plugin" (and then trimming to get rid of any whitespace).
+    // (Otherwise, something like "Java(TM) Plug-in 1.7.0_07" gets mangled)
+    let newName = aName
+      .replace(/\(.*?\)/g, "")
+      .replace(/[\s\d\.\-\_\(\)]+$/, "")
+      .replace(/\bplug-?in\b/i, "")
+      .trim();
+    return newName;
+  },
+
   /**
    * Returns true if |mimeType| is text-based, or false otherwise.
    *
@@ -124,12 +437,395 @@ var BrowserUtils = {
     );
   },
 
-  isFindbarVisible(docShell) {
-    const FINDER_JSM = "resource://gre/modules/Finder.jsm";
-    return (
-      Cu.isModuleLoaded(FINDER_JSM) &&
-      ChromeUtils.import(FINDER_JSM).Finder.isFindbarVisible(docShell)
+  _visibleToolbarsMap: new WeakMap(),
+
+  /**
+   * Return true if any or a specific toolbar that interacts with the content
+   * document is visible.
+   *
+   * @param  {nsIDocShell} docShell The docShell instance that a toolbar should
+   *                                be interacting with
+   * @param  {String}      which    Identifier of a specific toolbar
+   * @return {Boolean}
+   */
+  isToolbarVisible(docShell, which) {
+    let window = this.getRootWindow(docShell);
+    if (!this._visibleToolbarsMap.has(window)) {
+      return false;
+    }
+    let toolbars = this._visibleToolbarsMap.get(window);
+    return !!toolbars && toolbars.has(which);
+  },
+
+  /**
+   * Sets the --toolbarbutton-button-height CSS property on the closest
+   * toolbar to the provided element. Useful if you need to vertically
+   * center a position:absolute element within a toolbar that uses
+   * -moz-pack-align:stretch, and thus a height which is dependant on
+   * the font-size.
+   *
+   * @param element An element within the toolbar whose height is desired.
+   */
+  async setToolbarButtonHeightProperty(element) {
+    let window = element.ownerGlobal;
+    let dwu = window.windowUtils;
+    let toolbarItem = element;
+    let urlBarContainer = element.closest("#urlbar-container");
+    if (urlBarContainer) {
+      // The stop-reload-button, which is contained in #urlbar-container,
+      // needs to use #urlbar-container to calculate the bounds.
+      toolbarItem = urlBarContainer;
+    }
+    if (!toolbarItem) {
+      return;
+    }
+    let bounds = dwu.getBoundsWithoutFlushing(toolbarItem);
+    if (!bounds.height) {
+      await window.promiseDocumentFlushed(() => {
+        bounds = dwu.getBoundsWithoutFlushing(toolbarItem);
+      });
+    }
+    if (bounds.height) {
+      toolbarItem.style.setProperty(
+        "--toolbarbutton-height",
+        bounds.height + "px"
+      );
+    }
+  },
+
+  /**
+   * Track whether a toolbar is visible for a given a docShell.
+   *
+   * @param  {nsIDocShell} docShell  The docShell instance that a toolbar should
+   *                                 be interacting with
+   * @param  {String}      which     Identifier of a specific toolbar
+   * @param  {Boolean}     [visible] Whether the toolbar is visible. Optional,
+   *                                 defaults to `true`.
+   */
+  trackToolbarVisibility(docShell, which, visible = true) {
+    // We have to get the root window object, because XPConnect WrappedNatives
+    // can't be used as WeakMap keys.
+    let window = this.getRootWindow(docShell);
+    let toolbars = this._visibleToolbarsMap.get(window);
+    if (!toolbars) {
+      toolbars = new Set();
+      this._visibleToolbarsMap.set(window, toolbars);
+    }
+    if (!visible) {
+      toolbars.delete(which);
+    } else {
+      toolbars.add(which);
+    }
+  },
+
+  /**
+   * Retrieve the root window object (i.e. the top-most content global) for a
+   * specific docShell object.
+   *
+   * @param  {nsIDocShell} docShell
+   * @return {nsIDOMWindow}
+   */
+  getRootWindow(docShell) {
+    return docShell.browsingContext.top.window;
+  },
+
+  /**
+   * Trim the selection text to a reasonable size and sanitize it to make it
+   * safe for search query input.
+   *
+   * @param aSelection
+   *        The selection text to trim.
+   * @param aMaxLen
+   *        The maximum string length, defaults to a reasonable size if undefined.
+   * @return The trimmed selection text.
+   */
+  trimSelection(aSelection, aMaxLen) {
+    // Selections of more than 150 characters aren't useful.
+    const maxLen = Math.min(aMaxLen || 150, aSelection.length);
+
+    if (aSelection.length > maxLen) {
+      // only use the first maxLen important chars. see bug 221361
+      let pattern = new RegExp("^(?:\\s*.){0," + maxLen + "}");
+      pattern.test(aSelection);
+      aSelection = RegExp.lastMatch;
+    }
+
+    aSelection = aSelection.trim().replace(/\s+/g, " ");
+
+    if (aSelection.length > maxLen) {
+      aSelection = aSelection.substr(0, maxLen);
+    }
+
+    return aSelection;
+  },
+
+  /**
+   * Retrieve the text selection details for the given window.
+   *
+   * @param  aTopWindow
+   *         The top window of the element containing the selection.
+   * @param  aCharLen
+   *         The maximum string length for the selection text.
+   * @return The selection details containing the full and trimmed selection text
+   *         and link details for link selections.
+   */
+  getSelectionDetails(aTopWindow, aCharLen) {
+    let focusedWindow = {};
+    let focusedElement = Services.focus.getFocusedElementForWindow(
+      aTopWindow,
+      true,
+      focusedWindow
     );
+    focusedWindow = focusedWindow.value;
+
+    let selection = focusedWindow.getSelection();
+    let selectionStr = selection.toString();
+    let fullText;
+
+    let url;
+    let linkText;
+
+    let isDocumentLevelSelection = true;
+    // try getting a selected text in text input.
+    if (!selectionStr && focusedElement) {
+      // Don't get the selection for password fields. See bug 565717.
+      if (
+        ChromeUtils.getClassName(focusedElement) === "HTMLTextAreaElement" ||
+        (ChromeUtils.getClassName(focusedElement) === "HTMLInputElement" &&
+          focusedElement.mozIsTextField(true))
+      ) {
+        selection = focusedElement.editor.selection;
+        selectionStr = selection.toString();
+        isDocumentLevelSelection = false;
+      }
+    }
+
+    let collapsed = selection.isCollapsed;
+
+    if (selectionStr) {
+      // Have some text, let's figure out if it looks like a URL that isn't
+      // actually a link.
+      linkText = selectionStr.trim();
+      if (/^(?:https?|ftp):/i.test(linkText)) {
+        try {
+          url = this.makeURI(linkText);
+        } catch (ex) {}
+      } else if (/^(?:[a-z\d-]+\.)+[a-z]+$/i.test(linkText)) {
+        // Check if this could be a valid url, just missing the protocol.
+        // Now let's see if this is an intentional link selection. Our guess is
+        // based on whether the selection begins/ends with whitespace or is
+        // preceded/followed by a non-word character.
+
+        // selection.toString() trims trailing whitespace, so we look for
+        // that explicitly in the first and last ranges.
+        let beginRange = selection.getRangeAt(0);
+        let delimitedAtStart = /^\s/.test(beginRange);
+        if (!delimitedAtStart) {
+          let container = beginRange.startContainer;
+          let offset = beginRange.startOffset;
+          if (container.nodeType == container.TEXT_NODE && offset > 0) {
+            delimitedAtStart = /\W/.test(container.textContent[offset - 1]);
+          } else {
+            delimitedAtStart = true;
+          }
+        }
+
+        let delimitedAtEnd = false;
+        if (delimitedAtStart) {
+          let endRange = selection.getRangeAt(selection.rangeCount - 1);
+          delimitedAtEnd = /\s$/.test(endRange);
+          if (!delimitedAtEnd) {
+            let container = endRange.endContainer;
+            let offset = endRange.endOffset;
+            if (
+              container.nodeType == container.TEXT_NODE &&
+              offset < container.textContent.length
+            ) {
+              delimitedAtEnd = /\W/.test(container.textContent[offset]);
+            } else {
+              delimitedAtEnd = true;
+            }
+          }
+        }
+
+        if (delimitedAtStart && delimitedAtEnd) {
+          try {
+            url = Services.uriFixup.getFixupURIInfo(linkText).preferredURI;
+          } catch (ex) {}
+        }
+      }
+    }
+
+    if (selectionStr) {
+      // Pass up to 16K through unmolested.  If an add-on needs more, they will
+      // have to use a content script.
+      fullText = selectionStr.substr(0, 16384);
+      selectionStr = this.trimSelection(selectionStr, aCharLen);
+    }
+
+    if (url && !url.host) {
+      url = null;
+    }
+
+    return {
+      text: selectionStr,
+      docSelectionIsCollapsed: collapsed,
+      isDocumentLevelSelection,
+      fullText,
+      linkURL: url ? url.spec : null,
+      linkText: url ? linkText : "",
+    };
+  },
+
+  /**
+   * Replaces %s or %S in the provided url or postData with the given parameter,
+   * acccording to the best charset for the given url.
+   *
+   * @return [url, postData]
+   * @throws if nor url nor postData accept a param, but a param was provided.
+   */
+  async parseUrlAndPostData(url, postData, param) {
+    let hasGETParam = /%s/i.test(url);
+    let decodedPostData = postData ? unescape(postData) : "";
+    let hasPOSTParam = /%s/i.test(decodedPostData);
+
+    if (!hasGETParam && !hasPOSTParam) {
+      if (param) {
+        // If nor the url, nor postData contain parameters, but a parameter was
+        // provided, return the original input.
+        throw new Error(
+          "A param was provided but there's nothing to bind it to"
+        );
+      }
+      return [url, postData];
+    }
+
+    let charset = "";
+    const re = /^(.*)\&mozcharset=([a-zA-Z][_\-a-zA-Z0-9]+)\s*$/;
+    let matches = url.match(re);
+    if (matches) {
+      [, url, charset] = matches;
+    } else {
+      // Try to fetch a charset from History.
+      try {
+        // Will return an empty string if character-set is not found.
+        let pageInfo = await PlacesUtils.history.fetch(url, {
+          includeAnnotations: true,
+        });
+        if (pageInfo && pageInfo.annotations.has(PlacesUtils.CHARSET_ANNO)) {
+          charset = pageInfo.annotations.get(PlacesUtils.CHARSET_ANNO);
+        }
+      } catch (ex) {
+        // makeURI() throws if url is invalid.
+        Cu.reportError(ex);
+      }
+    }
+
+    // encodeURIComponent produces UTF-8, and cannot be used for other charsets.
+    // escape() works in those cases, but it doesn't uri-encode +, @, and /.
+    // Therefore we need to manually replace these ASCII characters by their
+    // encodeURIComponent result, to match the behavior of nsEscape() with
+    // url_XPAlphas.
+    let encodedParam = "";
+    if (charset && charset != "UTF-8") {
+      try {
+        let converter = Cc[
+          "@mozilla.org/intl/scriptableunicodeconverter"
+        ].createInstance(Ci.nsIScriptableUnicodeConverter);
+        converter.charset = charset;
+        encodedParam = converter.ConvertFromUnicode(param) + converter.Finish();
+      } catch (ex) {
+        encodedParam = param;
+      }
+      encodedParam = escape(encodedParam).replace(
+        /[+@\/]+/g,
+        encodeURIComponent
+      );
+    } else {
+      // Default charset is UTF-8
+      encodedParam = encodeURIComponent(param);
+    }
+
+    url = url.replace(/%s/g, encodedParam).replace(/%S/g, param);
+    if (hasPOSTParam) {
+      postData = decodedPostData
+        .replace(/%s/g, encodedParam)
+        .replace(/%S/g, param);
+    }
+    return [url, postData];
+  },
+
+  /**
+   * Generate a document fragment for a localized string that has DOM
+   * node replacements. This avoids using getFormattedString followed
+   * by assigning to innerHTML. Fluent can probably replace this when
+   * it is in use everywhere.
+   *
+   * @param {Document} doc
+   * @param {String}   msg
+   *                   The string to put replacements in. Fetch from
+   *                   a stringbundle using getString or GetStringFromName,
+   *                   or even an inserted dtd string.
+   * @param {Node|String} nodesOrStrings
+   *                   The replacement items. Can be a mix of Nodes
+   *                   and Strings. However, for correct behaviour, the
+   *                   number of items provided needs to exactly match
+   *                   the number of replacement strings in the l10n string.
+   * @returns {DocumentFragment}
+   *                   A document fragment. In the trivial case (no
+   *                   replacements), this will simply be a fragment with 1
+   *                   child, a text node containing the localized string.
+   */
+  getLocalizedFragment(doc, msg, ...nodesOrStrings) {
+    // Ensure replacement points are indexed:
+    for (let i = 1; i <= nodesOrStrings.length; i++) {
+      if (!msg.includes("%" + i + "$S")) {
+        msg = msg.replace(/%S/, "%" + i + "$S");
+      }
+    }
+    let numberOfInsertionPoints = msg.match(/%\d+\$S/g).length;
+    if (numberOfInsertionPoints != nodesOrStrings.length) {
+      Cu.reportError(
+        `Message has ${numberOfInsertionPoints} insertion points, ` +
+          `but got ${nodesOrStrings.length} replacement parameters!`
+      );
+    }
+
+    let fragment = doc.createDocumentFragment();
+    let parts = [msg];
+    let insertionPoint = 1;
+    for (let replacement of nodesOrStrings) {
+      let insertionString = "%" + insertionPoint++ + "$S";
+      let partIndex = parts.findIndex(
+        part => typeof part == "string" && part.includes(insertionString)
+      );
+      if (partIndex == -1) {
+        fragment.appendChild(doc.createTextNode(msg));
+        return fragment;
+      }
+
+      if (typeof replacement == "string") {
+        parts[partIndex] = parts[partIndex].replace(
+          insertionString,
+          replacement
+        );
+      } else {
+        let [firstBit, lastBit] = parts[partIndex].split(insertionString);
+        parts.splice(partIndex, 1, firstBit, replacement, lastBit);
+      }
+    }
+
+    // Put everything in a document fragment:
+    for (let part of parts) {
+      if (typeof part == "string") {
+        if (part) {
+          fragment.appendChild(doc.createTextNode(part));
+        }
+      } else {
+        fragment.appendChild(part);
+      }
+    }
+    return fragment;
   },
 
   /**
@@ -155,6 +851,231 @@ var BrowserUtils = {
       Services.obs.addObserver(observer, topic);
     });
   },
+
+  removeSingleTrailingSlashFromURL(aURL) {
+    // remove single trailing slash for http/https/ftp URLs
+    return aURL.replace(/^((?:http|https|ftp):\/\/[^/]+)\/$/, "$1");
+  },
+
+  /**
+   * Returns a URL which has been trimmed by removing 'http://' and any
+   * trailing slash (in http/https/ftp urls).
+   * Note that a trimmed url may not load the same page as the original url, so
+   * before loading it, it must be passed through URIFixup, to check trimming
+   * doesn't change its destination. We don't run the URIFixup check here,
+   * because trimURL is in the page load path (see onLocationChange), so it
+   * must be fast and simple.
+   *
+   * @param {string} aURL The URL to trim.
+   * @returns {string} The trimmed string.
+   */
+  get trimURLProtocol() {
+    return "http://";
+  },
+  trimURL(aURL) {
+    let url = this.removeSingleTrailingSlashFromURL(aURL);
+    // Remove "http://" prefix.
+    return url.startsWith(this.trimURLProtocol)
+      ? url.substring(this.trimURLProtocol.length)
+      : url;
+  },
+
+  recordSiteOriginTelemetry(aWindows, aIsGeckoView) {
+    Services.tm.idleDispatchToMainThread(() => {
+      this._recordSiteOriginTelemetry(aWindows, aIsGeckoView);
+    });
+  },
+
+  computeSiteOriginCount(aWindows, aIsGeckoView) {
+    // Geckoview and Desktop work differently. On desktop, aBrowser objects
+    // holds an array of tabs which we can use to get the <browser> objects.
+    // In Geckoview, it is apps' responsibility to keep track of the tabs, so
+    // there isn't an easy way for us to get the tabs.
+    let tabs = [];
+    if (aIsGeckoView) {
+      // To get all active windows; Each tab has its own window
+      tabs = aWindows;
+    } else {
+      for (const win of aWindows) {
+        tabs = tabs.concat(win.gBrowser.tabs);
+      }
+    }
+
+    let topLevelBCs = [];
+
+    for (const tab of tabs) {
+      let browser;
+      if (aIsGeckoView) {
+        browser = tab.browser;
+      } else {
+        browser = tab.linkedBrowser;
+      }
+
+      if (browser.browsingContext) {
+        // This is the top level browsingContext
+        topLevelBCs.push(browser.browsingContext);
+      }
+    }
+
+    return CanonicalBrowsingContext.countSiteOrigins(topLevelBCs);
+  },
+
+  _recordSiteOriginTelemetry(aWindows, aIsGeckoView) {
+    let currentTime = Date.now();
+
+    // default is 5 minutes
+    if (!this.min_interval) {
+      this.min_interval = Services.prefs.getIntPref(
+        "telemetry.number_of_site_origin.min_interval",
+        300000
+      );
+    }
+
+    let originCount = this.computeSiteOriginCount(aWindows, aIsGeckoView);
+    let histogram = Services.telemetry.getHistogramById(
+      "FX_NUMBER_OF_UNIQUE_SITE_ORIGINS_ALL_TABS"
+    );
+
+    // Discard the first load because most of the time the first load only has 1
+    // tab and 1 window open, so it is useless to report it.
+    if (!this._lastRecordSiteOrigin) {
+      this._lastRecordSiteOrigin = currentTime;
+    } else if (currentTime >= this._lastRecordSiteOrigin + this.min_interval) {
+      this._lastRecordSiteOrigin = currentTime;
+
+      histogram.add(originCount);
+    }
+
+    // Update the Fission experiment qualification state based on the
+    // current origin count:
+
+    // If we don't already have a last disqualification timestamp, look
+    // through the existing histogram values, and use the existing
+    // maximum value as the initial count. This will prevent us from
+    // enrolling users in the experiment if they have a history of
+    // exceeding our origin cap.
+    if (!this._checkedInitialExperimentQualification) {
+      this._checkedInitialExperimentQualification = true;
+      if (
+        !Services.prefs.prefHasUserValue(
+          FISSION_EXPERIMENT_PREF_LAST_DISQUALIFIED
+        )
+      ) {
+        for (let [bucketStr, entryCount] of Object.entries(
+          histogram.snapshot().values
+        )) {
+          let bucket = Number(bucketStr);
+          if (bucket > originCount && entryCount > 0) {
+            originCount = bucket;
+          }
+        }
+        Services.prefs.setIntPref(FISSION_EXPERIMENT_PREF_LAST_DISQUALIFIED, 0);
+      }
+    }
+
+    let currentTimeSec = currentTime / 1000;
+    if (originCount < fissionExperimentMaxOrigins) {
+      let lastDisqualified = fissionExperimentLastDisqualified;
+      let lastQualified = fissionExperimentLastQualified;
+
+      // If the last time we saw a qualifying origin count was earlier
+      // than the last time we say a disqualifying count, update any
+      // existing last disqualified timestamp to just before now, on the
+      // basis that our origin count has probably just fallen below the
+      // cap.
+      if (lastDisqualified > 0 && lastQualified <= lastDisqualified) {
+        Services.prefs.setIntPref(
+          FISSION_EXPERIMENT_PREF_LAST_DISQUALIFIED,
+          currentTimeSec - 1
+        );
+      }
+
+      if (!fissionExperimentQualified) {
+        Services.prefs.setIntPref(
+          FISSION_EXPERIMENT_PREF_LAST_QUALIFIED,
+          currentTimeSec
+        );
+
+        // We have a qualifying origin count now. If the last time we were
+        // disqualified was prior to the start of our current sliding
+        // window, re-qualify the user.
+        if (
+          currentTimeSec - lastDisqualified >=
+          fissionExperimentSlidingWindowMS / 1000
+        ) {
+          Services.prefs.setBoolPref(FISSION_EXPERIMENT_PREF_QUALIFIED, true);
+        }
+      }
+    } else {
+      Services.prefs.setIntPref(
+        FISSION_EXPERIMENT_PREF_LAST_DISQUALIFIED,
+        currentTimeSec
+      );
+      Services.prefs.setBoolPref(FISSION_EXPERIMENT_PREF_QUALIFIED, false);
+    }
+  },
+
+  /**
+   * Converts a property bag to object.
+   * @param {nsIPropertyBag} bag - The property bag to convert
+   * @returns {Object} - The object representation of the nsIPropertyBag
+   */
+  propBagToObject(bag) {
+    function toValue(property) {
+      if (typeof property != "object") {
+        return property;
+      }
+      if (Array.isArray(property)) {
+        return property.map(this.toValue, this);
+      }
+      if (property && property instanceof Ci.nsIPropertyBag) {
+        return this.propBagToObject(property);
+      }
+      return property;
+    }
+    if (!(bag instanceof Ci.nsIPropertyBag)) {
+      throw new TypeError("Not a property bag");
+    }
+    let result = {};
+    for (let { name, value: property } of bag.enumerator) {
+      let value = toValue(property);
+      result[name] = value;
+    }
+    return result;
+  },
+
+  /**
+   * Converts an object to a property bag.
+   * @param {Object} obj - The object to convert.
+   * @returns {nsIPropertyBag} - The property bag representation of the object.
+   */
+  objectToPropBag(obj) {
+    function fromValue(value) {
+      if (typeof value == "function") {
+        return null; // Emulating the behavior of JSON.stringify with functions
+      }
+      if (Array.isArray(value)) {
+        return value.map(this.fromValue, this);
+      }
+      if (value == null || typeof value != "object") {
+        // Auto-converted to nsIVariant
+        return value;
+      }
+      return this.objectToPropBag(value);
+    }
+
+    if (obj == null || typeof obj != "object") {
+      throw new TypeError("Invalid object: " + obj);
+    }
+    let bag = Cc["@mozilla.org/hash-property-bag;1"].createInstance(
+      Ci.nsIWritablePropertyBag
+    );
+    for (let k of Object.keys(obj)) {
+      let value = fromValue(obj[k]);
+      bag.setProperty(k, value);
+    }
+    return bag;
+  },
 };
 
 XPCOMUtils.defineLazyPreferenceGetter(
diff --git a/toolkit/modules/Finder.jsm b/toolkit/modules/Finder.jsm
index 6d5d8ed0f32c..bf544fe09246 100644
--- a/toolkit/modules/Finder.jsm
+++ b/toolkit/modules/Finder.jsm
@@ -15,6 +15,11 @@ const { XPCOMUtils } = ChromeUtils.import(
 const { Rect } = ChromeUtils.import("resource://gre/modules/Geometry.jsm");
 const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
 
+ChromeUtils.defineModuleGetter(
+  this,
+  "BrowserUtils",
+  "resource://gre/modules/BrowserUtils.jsm"
+);
 ChromeUtils.defineModuleGetter(
   this,
   "FinderIterator",
@@ -37,8 +42,6 @@ XPCOMUtils.defineLazyServiceGetter(
 const kSelectionMaxLen = 150;
 const kMatchesCountLimitPref = "accessibility.typeaheadfind.matchesCountLimit";
 
-const activeFinderRoots = new WeakSet();
-
 function Finder(docShell) {
   this._fastFind = Cc["@mozilla.org/typeaheadfind;1"].createInstance(
     Ci.nsITypeAheadFind
@@ -489,15 +492,11 @@ Finder.prototype = {
     this.enableSelection();
     this.highlighter.highlight(false);
     this.iterator.reset();
-    activeFinderRoots.delete(this._docShell.browsingContext.top);
+    BrowserUtils.trackToolbarVisibility(this._docShell, "findbar", false);
   },
 
   onFindbarOpen() {
-    activeFinderRoots.add(this._docShell.browsingContext.top);
-  },
-
-  isFindbarVisible(docShell) {
-    return activeFinderRoots.has(docShell.browsingContext.top);
+    BrowserUtils.trackToolbarVisibility(this._docShell, "findbar", true);
   },
 
   onModalHighlightChange(useModalHighlight) {
diff --git a/toolkit/modules/KeywordUtils.jsm b/toolkit/modules/KeywordUtils.jsm
deleted file mode 100644
index c47b44a37179..000000000000
--- a/toolkit/modules/KeywordUtils.jsm
+++ /dev/null
@@ -1,94 +0,0 @@
-/* -*- mode: js; indent-tabs-mode: nil; js-indent-level: 2 -*- */
-/* 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";
-
-var EXPORTED_SYMBOLS = ["KeywordUtils"];
-
-ChromeUtils.defineModuleGetter(
-  this,
-  "PlacesUtils",
-  "resource://gre/modules/PlacesUtils.jsm"
-);
-
-var KeywordUtils = {
-  /**
-   * Replaces %s or %S in the provided url or postData with the given parameter,
-   * acccording to the best charset for the given url.
-   *
-   * @return [url, postData]
-   * @throws if nor url nor postData accept a param, but a param was provided.
-   */
-  async parseUrlAndPostData(url, postData, param) {
-    let hasGETParam = /%s/i.test(url);
-    let decodedPostData = postData ? unescape(postData) : "";
-    let hasPOSTParam = /%s/i.test(decodedPostData);
-
-    if (!hasGETParam && !hasPOSTParam) {
-      if (param) {
-        // If nor the url, nor postData contain parameters, but a parameter was
-        // provided, return the original input.
-        throw new Error(
-          "A param was provided but there's nothing to bind it to"
-        );
-      }
-      return [url, postData];
-    }
-
-    let charset = "";
-    const re = /^(.*)\&mozcharset=([a-zA-Z][_\-a-zA-Z0-9]+)\s*$/;
-    let matches = url.match(re);
-    if (matches) {
-      [, url, charset] = matches;
-    } else {
-      // Try to fetch a charset from History.
-      try {
-        // Will return an empty string if character-set is not found.
-        let pageInfo = await PlacesUtils.history.fetch(url, {
-          includeAnnotations: true,
-        });
-        if (pageInfo && pageInfo.annotations.has(PlacesUtils.CHARSET_ANNO)) {
-          charset = pageInfo.annotations.get(PlacesUtils.CHARSET_ANNO);
-        }
-      } catch (ex) {
-        // makeURI() throws if url is invalid.
-        Cu.reportError(ex);
-      }
-    }
-
-    // encodeURIComponent produces UTF-8, and cannot be used for other charsets.
-    // escape() works in those cases, but it doesn't uri-encode +, @, and /.
-    // Therefore we need to manually replace these ASCII characters by their
-    // encodeURIComponent result, to match the behavior of nsEscape() with
-    // url_XPAlphas.
-    let encodedParam = "";
-    if (charset && charset != "UTF-8") {
-      try {
-        let converter = Cc[
-          "@mozilla.org/intl/scriptableunicodeconverter"
-        ].createInstance(Ci.nsIScriptableUnicodeConverter);
-        converter.charset = charset;
-        encodedParam = converter.ConvertFromUnicode(param) + converter.Finish();
-      } catch (ex) {
-        encodedParam = param;
-      }
-      encodedParam = escape(encodedParam).replace(
-        /[+@\/]+/g,
-        encodeURIComponent
-      );
-    } else {
-      // Default charset is UTF-8
-      encodedParam = encodeURIComponent(param);
-    }
-
-    url = url.replace(/%s/g, encodedParam).replace(/%S/g, param);
-    if (hasPOSTParam) {
-      postData = decodedPostData
-        .replace(/%s/g, encodedParam)
-        .replace(/%S/g, param);
-    }
-    return [url, postData];
-  },
-};
diff --git a/toolkit/modules/LayoutUtils.jsm b/toolkit/modules/LayoutUtils.jsm
deleted file mode 100644
index e644bd453c4c..000000000000
--- a/toolkit/modules/LayoutUtils.jsm
+++ /dev/null
@@ -1,86 +0,0 @@
-/* -*- mode: js; indent-tabs-mode: nil; js-indent-level: 2 -*- */
-/* 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";
-
-var EXPORTED_SYMBOLS = ["LayoutUtils"];
-
-var LayoutUtils = {
-  /**
-   * For a given DOM element, returns its position in "screen"
-   * coordinates. In a content process, the coordinates returned will
-   * be relative to the left/top of the tab. In the chrome process,
-   * the coordinates are relative to the user's screen.
-   */
-  getElementBoundingScreenRect(aElement) {
-    return this.getElementBoundingRect(aElement, true);
-  },
-
-  /**
-   * For a given DOM element, returns its position as an offset from the topmost
-   * window. In a content process, the coordinates returned will be relative to
-   * the left/top of the topmost content area. If aInScreenCoords is true,
-   * screen coordinates will be returned instead.
-   */
-  getElementBoundingRect(aElement, aInScreenCoords) {
-    let rect = aElement.getBoundingClientRect();
-    let win = aElement.ownerGlobal;
-
-    let x = rect.left;
-    let y = rect.top;
-
-    // We need to compensate for any iframes that might shift things
-    // over. We also need to compensate for zooming.
-    let parentFrame = win.frameElement;
-    while (parentFrame) {
-      win = parentFrame.ownerGlobal;
-      let cstyle = win.getComputedStyle(parentFrame);
-
-      let framerect = parentFrame.getBoundingClientRect();
-      x +=
-        framerect.left +
-        parseFloat(cstyle.borderLeftWidth) +
-        parseFloat(cstyle.paddingLeft);
-      y +=
-        framerect.top +
-        parseFloat(cstyle.borderTopWidth) +
-        parseFloat(cstyle.paddingTop);
-
-      parentFrame = win.frameElement;
-    }
-
-    rect = {
-      left: x,
-      top: y,
-      width: rect.width,
-      height: rect.height,
-    };
-    rect = win.windowUtils.transformRectLayoutToVisual(
-      rect.left,
-      rect.top,
-      rect.width,
-      rect.height
-    );
-
-    if (aInScreenCoords) {
-      rect = {
-        left: rect.left + win.mozInnerScreenX,
-        top: rect.top + win.mozInnerScreenY,
-        width: rect.width,
-        height: rect.height,
-      };
-    }
-
-    let fullZoom = win.windowUtils.fullZoom;
-    rect = {
-      left: rect.left * fullZoom,
-      top: rect.top * fullZoom,
-      width: rect.width * fullZoom,
-      height: rect.height * fullZoom,
-    };
-
-    return rect;
-  },
-};
diff --git a/toolkit/modules/SelectionUtils.jsm b/toolkit/modules/SelectionUtils.jsm
deleted file mode 100644
index c214867da963..000000000000
--- a/toolkit/modules/SelectionUtils.jsm
+++ /dev/null
@@ -1,160 +0,0 @@
-/* -*- mode: js; indent-tabs-mode: nil; js-indent-level: 2 -*- */
-/* 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";
-
-var EXPORTED_SYMBOLS = ["SelectionUtils"];
-
-const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
-
-var SelectionUtils = {
-  /**
-   * Trim the selection text to a reasonable size and sanitize it to make it
-   * safe for search query input.
-   *
-   * @param aSelection
-   *        The selection text to trim.
-   * @param aMaxLen
-   *        The maximum string length, defaults to a reasonable size if undefined.
-   * @return The trimmed selection text.
-   */
-  trimSelection(aSelection, aMaxLen) {
-    // Selections of more than 150 characters aren't useful.
-    const maxLen = Math.min(aMaxLen || 150, aSelection.length);
-
-    if (aSelection.length > maxLen) {
-      // only use the first maxLen important chars. see bug 221361
-      let pattern = new RegExp("^(?:\\s*.){0," + maxLen + "}");
-      pattern.test(aSelection);
-      aSelection = RegExp.lastMatch;
-    }
-
-    aSelection = aSelection.trim().replace(/\s+/g, " ");
-
-    if (aSelection.length > maxLen) {
-      aSelection = aSelection.substr(0, maxLen);
-    }
-
-    return aSelection;
-  },
-
-  /**
-   * Retrieve the text selection details for the given window.
-   *
-   * @param  aTopWindow
-   *         The top window of the element containing the selection.
-   * @param  aCharLen
-   *         The maximum string length for the selection text.
-   * @return The selection details containing the full and trimmed selection text
-   *         and link details for link selections.
-   */
-  getSelectionDetails(aTopWindow, aCharLen) {
-    let focusedWindow = {};
-    let focusedElement = Services.focus.getFocusedElementForWindow(
-      aTopWindow,
-      true,
-      focusedWindow
-    );
-    focusedWindow = focusedWindow.value;
-
-    let selection = focusedWindow.getSelection();
-    let selectionStr = selection.toString();
-    let fullText;
-
-    let url;
-    let linkText;
-
-    let isDocumentLevelSelection = true;
-    // try getting a selected text in text input.
-    if (!selectionStr && focusedElement) {
-      // Don't get the selection for password fields. See bug 565717.
-      if (
-        ChromeUtils.getClassName(focusedElement) === "HTMLTextAreaElement" ||
-        (ChromeUtils.getClassName(focusedElement) === "HTMLInputElement" &&
-          focusedElement.mozIsTextField(true))
-      ) {
-        selection = focusedElement.editor.selection;
-        selectionStr = selection.toString();
-        isDocumentLevelSelection = false;
-      }
-    }
-
-    let collapsed = selection.isCollapsed;
-
-    if (selectionStr) {
-      // Have some text, let's figure out if it looks like a URL that isn't
-      // actually a link.
-      linkText = selectionStr.trim();
-      if (/^(?:https?|ftp):/i.test(linkText)) {
-        try {
-          url = Services.io.newURI(linkText);
-        } catch (ex) {}
-      } else if (/^(?:[a-z\d-]+\.)+[a-z]+$/i.test(linkText)) {
-        // Check if this could be a valid url, just missing the protocol.
-        // Now let's see if this is an intentional link selection. Our guess is
-        // based on whether the selection begins/ends with whitespace or is
-        // preceded/followed by a non-word character.
-
-        // selection.toString() trims trailing whitespace, so we look for
-        // that explicitly in the first and last ranges.
-        let beginRange = selection.getRangeAt(0);
-        let delimitedAtStart = /^\s/.test(beginRange);
-        if (!delimitedAtStart) {
-          let container = beginRange.startContainer;
-          let offset = beginRange.startOffset;
-          if (container.nodeType == container.TEXT_NODE && offset > 0) {
-            delimitedAtStart = /\W/.test(container.textContent[offset - 1]);
-          } else {
-            delimitedAtStart = true;
-          }
-        }
-
-        let delimitedAtEnd = false;
-        if (delimitedAtStart) {
-          let endRange = selection.getRangeAt(selection.rangeCount - 1);
-          delimitedAtEnd = /\s$/.test(endRange);
-          if (!delimitedAtEnd) {
-            let container = endRange.endContainer;
-            let offset = endRange.endOffset;
-            if (
-              container.nodeType == container.TEXT_NODE &&
-              offset < container.textContent.length
-            ) {
-              delimitedAtEnd = /\W/.test(container.textContent[offset]);
-            } else {
-              delimitedAtEnd = true;
-            }
-          }
-        }
-
-        if (delimitedAtStart && delimitedAtEnd) {
-          try {
-            url = Services.uriFixup.getFixupURIInfo(linkText).preferredURI;
-          } catch (ex) {}
-        }
-      }
-    }
-
-    if (selectionStr) {
-      // Pass up to 16K through unmolested.  If an add-on needs more, they will
-      // have to use a content script.
-      fullText = selectionStr.substr(0, 16384);
-      selectionStr = this.trimSelection(selectionStr, aCharLen);
-    }
-
-    if (url && !url.host) {
-      url = null;
-    }
-
-    return {
-      text: selectionStr,
-      docSelectionIsCollapsed: collapsed,
-      isDocumentLevelSelection,
-      fullText,
-      linkURL: url ? url.spec : null,
-      linkText: url ? linkText : "",
-    };
-  },
-};
diff --git a/toolkit/modules/moz.build b/toolkit/modules/moz.build
index 88676f6f303f..e89953612a2f 100644
--- a/toolkit/modules/moz.build
+++ b/toolkit/modules/moz.build
@@ -160,7 +160,6 @@ EXTRA_JS_MODULES += [
     "AppMenuNotifications.jsm",
     "AsyncPrefs.jsm",
     "BinarySearch.jsm",
-    "BrowserTelemetryUtils.jsm",
     "BrowserUtils.jsm",
     "CanonicalJSON.jsm",
     "CertUtils.jsm",
@@ -191,8 +190,6 @@ EXTRA_JS_MODULES += [
     "InlineSpellCheckerContent.jsm",
     "Integration.jsm",
     "JSONFile.jsm",
-    "KeywordUtils.jsm",
-    "LayoutUtils.jsm",
     "Log.jsm",
     "NewTabUtils.jsm",
     "NLP.jsm",
@@ -213,7 +210,6 @@ EXTRA_JS_MODULES += [
     "RemotePageAccessManager.jsm",
     "ResetProfile.jsm",
     "ResponsivenessMonitor.jsm",
-    "SelectionUtils.jsm",
     "ServiceRequest.jsm",
     "Services.jsm",
     "ShortcutUtils.jsm",
diff --git a/toolkit/modules/tests/browser/browser_BrowserUtils.js b/toolkit/modules/tests/browser/browser_BrowserUtils.js
index 17353c88bea5..a20700fc7877 100644
--- a/toolkit/modules/tests/browser/browser_BrowserUtils.js
+++ b/toolkit/modules/tests/browser/browser_BrowserUtils.js
@@ -2,14 +2,18 @@
  * 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/. */
 
+const { BrowserUtils } = ChromeUtils.import(
+  "resource://gre/modules/BrowserUtils.jsm"
+);
+
 add_task(async function test_getSelectionDetails_input() {
   // Mostly a regression test for bug 1420560
   const url = kFixtureBaseURL + "file_getSelectionDetails_inputs.html";
   await BrowserTestUtils.withNewTab({ gBrowser, url }, async browser => {
     await SpecialPowers.spawn(browser, [], () => {
       function checkSelection({ id, text, linkURL }) {
-        const { SelectionUtils } = ChromeUtils.import(
-          "resource://gre/modules/SelectionUtils.jsm"
+        const { BrowserUtils } = ChromeUtils.import(
+          "resource://gre/modules/BrowserUtils.jsm"
         );
         content.document.getElementById(id).select();
         // It seems that when running as a test, the previous line will set
@@ -19,7 +23,7 @@ add_task(async function test_getSelectionDetails_input() {
         // ensure we're doing the right thing in the case that only the input's
         // selection is present.
         content.getSelection().removeAllRanges();
-        let info = SelectionUtils.getSelectionDetails(content);
+        let info = BrowserUtils.getSelectionDetails(content);
         Assert.equal(text, info.text);
         Assert.ok(!info.collapsed);
         Assert.equal(linkURL, info.linkURL);