From f94aaeb4a299fece2eef50ee13951387c32e13ba Mon Sep 17 00:00:00 2001
From: Jared Wein <jwein@mozilla.com>
Date: Wed, 17 Jun 2020 01:34:27 +0000
Subject: [PATCH] Bug 1644535 - Add section to about:preferences for
 Experimental Features. r=Gijs,fluent-reviewers

Differential Revision: https://phabricator.services.mozilla.com/D79023
---
 browser/app/profile/firefox.js                |  2 +-
 .../preferences/experimental.inc.xhtml        | 19 +++++++++++++++++++
 .../components/preferences/experimental.js    |  7 +++++++
 browser/components/preferences/jar.mn         |  1 +
 browser/components/preferences/preferences.js |  5 +++++
 .../components/preferences/preferences.xhtml  | 13 +++++++++++++
 .../en-US/browser/preferences/preferences.ftl |  6 ++++++
 .../shared/preferences/preferences.inc.css    | 11 +++++++++++
 8 files changed, 63 insertions(+), 1 deletion(-)
 create mode 100644 browser/components/preferences/experimental.inc.xhtml
 create mode 100644 browser/components/preferences/experimental.js

diff --git a/browser/app/profile/firefox.js b/browser/app/profile/firefox.js
index 10b7a3e1cc74..3b55c632949e 100644
--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -739,7 +739,7 @@ pref("plugins.favorfallback.rules", "nosrc,video");
 
 // Toggling Search bar on and off in about:preferences
 pref("browser.preferences.search", true);
-
+pref("browser.preferences.experimental", false);
 pref("browser.preferences.defaultPerformanceSettings.enabled", true);
 
 pref("browser.download.show_plugins_in_list", true);
diff --git a/browser/components/preferences/experimental.inc.xhtml b/browser/components/preferences/experimental.inc.xhtml
new file mode 100644
index 000000000000..f7862a8fdd92
--- /dev/null
+++ b/browser/components/preferences/experimental.inc.xhtml
@@ -0,0 +1,19 @@
+# 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/.
+
+<!-- Experimental panel -->
+
+<script src="chrome://browser/content/preferences/experimental.js"/>
+<html:template id="template-paneExperimental">
+<html:div id="firefoxExperimentalCategory"
+          class="subcategory"
+          hidden="true"
+          data-category="paneExperimental">
+  <html:h1 style="-moz-box-flex: 1;"
+           data-l10n-id="pane-experimental-title"/>
+  <html:h2 id="pane-experimental-subtitle"
+           data-l10n-id="pane-experimental-subtitle"/>
+  <html:p data-l10n-id="pane-experimental-description"/>
+</html:div>
+</html:template>
diff --git a/browser/components/preferences/experimental.js b/browser/components/preferences/experimental.js
new file mode 100644
index 000000000000..ae6615cf0f8e
--- /dev/null
+++ b/browser/components/preferences/experimental.js
@@ -0,0 +1,7 @@
+/* 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/. */
+
+var gExperimentalPane = {
+  init() {},
+};
diff --git a/browser/components/preferences/jar.mn b/browser/components/preferences/jar.mn
index 77f0ed206c6f..9d706a711d86 100644
--- a/browser/components/preferences/jar.mn
+++ b/browser/components/preferences/jar.mn
@@ -14,6 +14,7 @@ browser.jar:
    content/browser/preferences/privacy.js
    content/browser/preferences/containers.js
    content/browser/preferences/sync.js
+   content/browser/preferences/experimental.js
    content/browser/preferences/fxaPairDevice.xhtml
    content/browser/preferences/fxaPairDevice.js
    content/browser/preferences/findInPage.js
diff --git a/browser/components/preferences/preferences.js b/browser/components/preferences/preferences.js
index 27e9763a1f9e..0684ba643822 100644
--- a/browser/components/preferences/preferences.js
+++ b/browser/components/preferences/preferences.js
@@ -10,6 +10,7 @@
 /* import-globals-from containers.js */
 /* import-globals-from privacy.js */
 /* import-globals-from sync.js */
+/* import-globals-from experimental.js */
 /* import-globals-from findInPage.js */
 /* import-globals-from ../../base/content/utilityOverlay.js */
 /* import-globals-from ../../../toolkit/content/preferencesBindings.js */
@@ -90,6 +91,10 @@ function init_all() {
     // Remove the pane from the DOM so it doesn't get incorrectly included in search results.
     document.getElementById("template-paneSync").remove();
   }
+  if (Services.prefs.getBoolPref("browser.preferences.experimental")) {
+    document.getElementById("category-experimental").hidden = false;
+    register_module("paneExperimental", gExperimentalPane);
+  }
   register_module("paneSearchResults", gSearchResultsPane);
   gSearchResultsPane.init();
   gMainPane.preInit();
diff --git a/browser/components/preferences/preferences.xhtml b/browser/components/preferences/preferences.xhtml
index c8adb60653b7..cfa21090cc78 100644
--- a/browser/components/preferences/preferences.xhtml
+++ b/browser/components/preferences/preferences.xhtml
@@ -137,6 +137,18 @@
           <image class="category-icon"/>
           <label class="category-name" flex="1" data-l10n-id="pane-sync-title2"></label>
         </richlistitem>
+
+        <richlistitem id="category-experimental"
+                      class="category"
+                      hidden="true"
+                      value="paneExperimental"
+                      helpTopic="prefs-experimental"
+                      data-l10n-id="category-experimental"
+                      data-l10n-attrs="tooltiptext"
+                      align="center">
+          <image class="category-icon"/>
+          <label class="category-name" flex="1" data-l10n-id="pane-experimental-title"></label>
+        </richlistitem>
       </richlistbox>
 
       <spacer flex="1"/>
@@ -196,6 +208,7 @@
 #include privacy.inc.xhtml
 #include containers.inc.xhtml
 #include sync.inc.xhtml
+#include experimental.inc.xhtml
         </vbox>
       </vbox>
     </vbox>
diff --git a/browser/locales/en-US/browser/preferences/preferences.ftl b/browser/locales/en-US/browser/preferences/preferences.ftl
index ca3d8e8e3f18..53c6294fa219 100644
--- a/browser/locales/en-US/browser/preferences/preferences.ftl
+++ b/browser/locales/en-US/browser/preferences/preferences.ftl
@@ -53,6 +53,12 @@ pane-sync-title2 = { -sync-brand-short-name }
 category-sync2 =
     .tooltiptext = { pane-sync-title2 }
 
+pane-experimental-title = { -brand-short-name } Experiments
+category-experimental =
+    .tooltiptext = { -brand-short-name } Experiments
+pane-experimental-subtitle = Proceed with Caution
+pane-experimental-description = Changing advanced configuration preferences can impact { -brand-short-name } performance or security.
+
 help-button-label = { -brand-short-name } Support
 addons-button-label = Extensions & Themes
 
diff --git a/browser/themes/shared/preferences/preferences.inc.css b/browser/themes/shared/preferences/preferences.inc.css
index 5a31206b1511..07b7fed9eb17 100644
--- a/browser/themes/shared/preferences/preferences.inc.css
+++ b/browser/themes/shared/preferences/preferences.inc.css
@@ -1104,3 +1104,14 @@ richlistitem .text-link:hover {
   grid-column: span 2;
   height: 20px;
 }
+
+#pane-experimental-subtitle {
+  background-image: url("chrome://global/skin/icons/warning.svg");
+  background-repeat: no-repeat;
+  background-position: 0 center;
+  background-size: contain;
+  min-height: 30px;
+  padding-inline-start: 38px;
+  display: flex;
+  align-items: center;
+}