--- a/browser/base/content/browser-context.inc
+++ b/browser/base/content/browser-context.inc
@@ -1,16 +1,13 @@
 # -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 # 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/.
 
-# NB: IF YOU ADD ITEMS TO THIS FILE, PLEASE UPDATE THE WHITELIST IN
-# BrowserUITelemetry.jsm. SEE BUG 991757 FOR DETAILS.
-
       <menugroup id="context-navigation">
         <menuitem id="context-back"
                   class="menuitem-iconic"
                   tooltiptext="&backButton.tooltip;"
                   aria-label="&backCmd.label;"
                   command="Browser:BackOrBackDuplicate"
                   accesskey="&backCmd.accesskey;"
                   onclick="checkForMiddleClick(this, event);"/>

--- a/browser/base/content/browser-sidebar.js
+++ b/browser/base/content/browser-sidebar.js
@@ -388,17 +388,16 @@ var SidebarUI = {
     return this._show(commandID).then((sidebarBroadcaster) => {
       this._loadSidebarExtension(sidebarBroadcaster);
 
       if (triggerNode) {
         updateToggleControlLabel(triggerNode);
       }
 
       this._fireFocusedEvent();
-      BrowserUITelemetry.countSidebarEvent(commandID, "show");
     });
   },
 
   /**
    * Show the sidebar, without firing the focused event or logging telemetry.
    * This is intended to be used when the sidebar is opened automatically
    * when a window opens (not triggered by user interaction).
    *
@@ -419,20 +418,16 @@ var SidebarUI = {
   _show(commandID) {
     return new Promise((resolve, reject) => {
       let sidebarBroadcaster = this.getBroadcasterById(commandID);
       if (!sidebarBroadcaster) {
         reject(new Error("Invalid sidebar broadcaster specified: " + commandID));
         return;
       }
 
-      if (this.isOpen && commandID != this.currentID) {
-        BrowserUITelemetry.countSidebarEvent(this.currentID, "hide");
-      }
-
       let broadcasters = document.querySelectorAll("broadcaster[group=sidebar]");
       for (let broadcaster of broadcasters) {
         if (broadcaster != sidebarBroadcaster) {
           broadcaster.removeAttribute("checked");
         } else {
           sidebarBroadcaster.setAttribute("checked", "true");
         }
       }
@@ -530,17 +525,16 @@ var SidebarUI = {
     let selBrowser = gBrowser.selectedBrowser;
     selBrowser.focus();
     selBrowser.messageManager.sendAsyncMessage("Sidebar:VisibilityChange",
       {commandID, isOpen: false}
     );
     if (triggerNode) {
       updateToggleControlLabel(triggerNode);
     }
-    BrowserUITelemetry.countSidebarEvent(commandID, "hide");
   },
 };
 
 // Add getters related to the position here, since we will want them
 // available for both startDelayedLoad and init.
 XPCOMUtils.defineLazyPreferenceGetter(SidebarUI, "_positionStart",
   SidebarUI.POSITION_START_PREF, true, SidebarUI.setPosition.bind(SidebarUI));
 XPCOMUtils.defineLazyGetter(SidebarUI, "isRTL", () => {

--- a/browser/base/content/nsContextMenu.js
+++ b/browser/base/content/nsContextMenu.js
@@ -145,19 +145,16 @@ nsContextMenu.prototype = {
     this.onPlainTextLink = false;
 
     let bookmarkPage = document.getElementById("context-bookmarkpage");
     if (bookmarkPage)
       BookmarkingUI.onCurrentPageContextPopupShowing();
 
     // Initialize (disable/remove) menu items.
     this.initItems();
-
-    // Register this opening of the menu with telemetry:
-    this._checkTelemetryForMenu(aXulMenu);
   },
 
   setContext() {
     let context = Object.create(null);
     this.isRemote = false;
 
     if (gContextMenuContentData) {
       context = gContextMenuContentData.context;
@@ -1523,74 +1520,16 @@ nsContextMenu.prototype = {
     let engineName = Services.search.currentEngine.name;
     var menuLabel = gNavigatorBundle.getFormattedString("contextMenuSearch",
                                                         [engineName,
                                                          selectedText]);
     menuItem.label = menuLabel;
     menuItem.accessKey = gNavigatorBundle.getString("contextMenuSearch.accesskey");
   },
 
-  _getTelemetryClickInfo(aXulMenu) {
-    this._onPopupHiding = () => {
-      aXulMenu.ownerDocument.removeEventListener("command", activationHandler, true);
-      aXulMenu.removeEventListener("popuphiding", this._onPopupHiding, true);
-      delete this._onPopupHiding;
-
-      let eventKey = [
-          this._telemetryPageContext,
-          this._telemetryHadCustomItems ? "withcustom" : "withoutcustom"
-      ];
-      let target = this._telemetryClickID || "close-without-interaction";
-      BrowserUITelemetry.registerContextMenuInteraction(eventKey, target);
-    };
-    let activationHandler = (e) => {
-      // Deal with command events being routed to command elements; figure out
-      // what triggered the event (which will have the right e.target)
-      if (e.sourceEvent) {
-        e = e.sourceEvent;
-      }
-      // Target should be in the menu (this catches using shortcuts for items
-      // not in the menu while the menu is up)
-      if (!aXulMenu.contains(e.target)) {
-        return;
-      }
-
-      // Check if this is a page menu item:
-      if (e.target.hasAttribute(PageMenuParent.GENERATEDITEMID_ATTR)) {
-        this._telemetryClickID = "custom-page-item";
-      } else {
-        this._telemetryClickID = (e.target.id || "unknown").replace(/^context-/i, "");
-      }
-    };
-    aXulMenu.ownerDocument.addEventListener("command", activationHandler, true);
-    aXulMenu.addEventListener("popuphiding", this._onPopupHiding, true);
-  },
-
-  _getTelemetryPageContextInfo() {
-    let rv = [];
-    for (let k of ["isContentSelected", "onLink", "onImage", "onCanvas", "onVideo", "onAudio",
-                   "onTextInput", "inWebExtBrowser", "inTabBrowser"]) {
-      if (this[k]) {
-        rv.push(k.replace(/^(?:is|on)(.)/, (match, firstLetter) => firstLetter.toLowerCase()));
-      }
-    }
-    if (!rv.length) {
-      rv.push("other");
-    }
-
-    return JSON.stringify(rv);
-  },
-
-  _checkTelemetryForMenu(aXulMenu) {
-    this._telemetryClickID = null;
-    this._telemetryPageContext = this._getTelemetryPageContextInfo();
-    this._telemetryHadCustomItems = this.hasPageMenu;
-    this._getTelemetryClickInfo(aXulMenu);
-  },
-
   createContainerMenu(aEvent) {
     let createMenuOptions = {
       isContextMenu: true,
       excludeUserContextId: gContextMenuContentData.userContextId,
     };
     return createUserContextMenu(aEvent, createMenuOptions);
   },
 };

--- a/browser/base/content/tabbrowser.xml
+++ b/browser/base/content/tabbrowser.xml
@@ -1897,25 +1897,23 @@
             this.finishMediaBlockTimer();
           } else {
             if (browser.audioMuted) {
               if (this.linkedPanel) {
                 // "Lazy Browser" should not invoke its unmute method
                 browser.unmute();
               }
               this.removeAttribute("muted");
-              BrowserUITelemetry.countTabMutingEvent("unmute", aMuteReason);
               hist.add(1 /* unmute */);
             } else {
               if (this.linkedPanel) {
                 // "Lazy Browser" should not invoke its mute method
                 browser.mute();
               }
               this.setAttribute("muted", "true");
-              BrowserUITelemetry.countTabMutingEvent("mute", aMuteReason);
               hist.add(0 /* mute */);
             }
             this.muteReason = aMuteReason || null;
             modifiedAttrs.push("muted");
           }
           gBrowser._tabAttrModified(this, modifiedAttrs);
         ]]>
         </body>

--- a/browser/components/customizableui/CustomizableWidgets.jsm
+++ b/browser/components/customizableui/CustomizableWidgets.jsm
@@ -7,17 +7,16 @@
 var EXPORTED_SYMBOLS = ["CustomizableWidgets"];
 
 ChromeUtils.import("resource:///modules/CustomizableUI.jsm");
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 ChromeUtils.import("resource://gre/modules/AppConstants.jsm");
 
 XPCOMUtils.defineLazyModuleGetters(this, {
-  BrowserUITelemetry: "resource:///modules/BrowserUITelemetry.jsm",
   PanelView: "resource:///modules/PanelMultiView.jsm",
   RecentlyClosedTabsAndWindowsMenuUtils: "resource:///modules/sessionstore/RecentlyClosedTabsAndWindowsMenuUtils.jsm",
   ShortcutUtils: "resource://gre/modules/ShortcutUtils.jsm",
   CharsetMenu: "resource://gre/modules/CharsetMenu.jsm",
   PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.jsm",
   Sanitizer: "resource:///modules/Sanitizer.jsm",
   SyncedTabs: "resource://services-sync/SyncedTabs.jsm",
 });
@@ -742,17 +741,16 @@ if (Services.prefs.getBoolPref("identity
           triggeringPrincipal: Services.scriptSecurityManager.createNullPrincipal({})
         });
         if (doc.defaultView.whereToOpenLink(e) != "current") {
           e.preventDefault();
           e.stopPropagation();
         } else {
           CustomizableUI.hidePanelForNode(item);
         }
-        BrowserUITelemetry.countSyncedTabEvent("open", "toolbarbutton-subview");
       });
       return item;
     },
     _createShowMoreElement(doc, clientId, showCount) {
       let labelAttr, tooltipAttr;
       if (showCount === Infinity) {
         labelAttr = "showAllLabel";
         tooltipAttr = "showAllTooltipText";
@@ -799,17 +797,16 @@ if (Services.prefs.getBoolPref("privacy.
   CustomizableWidgets.push({
     id: "panic-button",
     type: "view",
     viewId: "PanelUI-panicView",
 
     forgetButtonCalled(aEvent) {
       let doc = aEvent.target.ownerDocument;
       let group = doc.getElementById("PanelUI-panic-timeSpan");
-      BrowserUITelemetry.countPanicEvent(group.selectedItem.id);
       let itemsToClear = [
         "cookies", "history", "openWindows", "formdata", "sessions", "cache", "downloads", "offlineApps"
       ];
       let newWindowPrivateState = PrivateBrowsingUtils.isWindowPrivate(doc.defaultView) ?
                                   "private" : "non-private";
       let promise = Sanitizer.sanitize(itemsToClear, {
         ignoreTimespan: false,
         range: Sanitizer.getClearRange(+group.value),

--- a/browser/components/customizableui/CustomizeMode.jsm
+++ b/browser/components/customizableui/CustomizeMode.jsm
@@ -26,18 +26,16 @@ ChromeUtils.import("resource:///modules/
 ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 ChromeUtils.import("resource://gre/modules/AddonManager.jsm");
 ChromeUtils.import("resource://gre/modules/AppConstants.jsm");
 
 XPCOMUtils.defineLazyGlobalGetters(this, ["CSS"]);
 
 ChromeUtils.defineModuleGetter(this, "DragPositionManager",
                                "resource:///modules/DragPositionManager.jsm");
-ChromeUtils.defineModuleGetter(this, "BrowserUITelemetry",
-                               "resource:///modules/BrowserUITelemetry.jsm");
 ChromeUtils.defineModuleGetter(this, "BrowserUtils",
                                "resource://gre/modules/BrowserUtils.jsm");
 ChromeUtils.defineModuleGetter(this, "LightweightThemeManager",
                                "resource://gre/modules/LightweightThemeManager.jsm");
 ChromeUtils.defineModuleGetter(this, "SessionStore",
                                "resource:///modules/sessionstore/SessionStore.jsm");
 XPCOMUtils.defineLazyGetter(this, "gWidgetsBundle", function() {
   const kUrl = "chrome://browser/locale/customizableui/customizableWidgets.properties";
@@ -1079,17 +1077,16 @@ CustomizeMode.prototype = {
       document.persist(toolbar.id, "currentset");
     }
   },
 
   reset() {
     this.resetting = true;
     // Disable the reset button temporarily while resetting:
     let btn = this.$("customization-reset-button");
-    BrowserUITelemetry.countCustomizationEvent("reset");
     btn.disabled = true;
     return (async () => {
       await this.depopulatePalette();
       await this._unwrapToolbarItems();
 
       CustomizableUI.reset();
 
       this._updateLWThemeButtonIcon();
@@ -1887,17 +1884,16 @@ CustomizeMode.prototype = {
     if (aTargetArea.id == kPaletteId) {
       // Did we drag from outside the palette?
       if (aOriginArea.id !== kPaletteId) {
         if (!CustomizableUI.isWidgetRemovable(aDraggedItemId)) {
           return;
         }
 
         CustomizableUI.removeWidgetFromArea(aDraggedItemId);
-        BrowserUITelemetry.countCustomizationEvent("remove");
         // Special widgets are removed outright, we can return here:
         if (CustomizableUI.isSpecialWidget(aDraggedItemId)) {
           return;
         }
       }
       draggedItem = draggedItem.parentNode;
 
       // If the target node is the palette itself, just append
@@ -1929,30 +1925,23 @@ CustomizeMode.prototype = {
       if (aTargetNode == aTargetArea.customizationTarget) {
         aTargetArea.customizationTarget.appendChild(draggedItem);
       } else {
         this.unwrapToolbarItem(aTargetNode.parentNode);
         aTargetArea.customizationTarget.insertBefore(draggedItem, aTargetNode);
         this.wrapToolbarItem(aTargetNode, place);
       }
       this.wrapToolbarItem(draggedItem, place);
-      BrowserUITelemetry.countCustomizationEvent("move");
       return;
     }
 
     // Is the target the customization area itself? If so, we just add the
     // widget to the end of the area.
     if (aTargetNode == aTargetArea.customizationTarget) {
       CustomizableUI.addWidgetToArea(aDraggedItemId, aTargetArea.id);
-      // For the purposes of BrowserUITelemetry, we consider both moving a widget
-      // within the same area, and adding a widget from one area to another area
-      // as a "move". An "add" is only when we move an item from the palette into
-      // an area.
-      let custEventType = aOriginArea.id == kPaletteId ? "add" : "move";
-      BrowserUITelemetry.countCustomizationEvent(custEventType);
       this._onDragEnd(aEvent);
       return;
     }
 
     // We need to determine the place that the widget is being dropped in
     // the target.
     let placement;
     let itemForPlacement = aTargetNode;
@@ -1987,21 +1976,16 @@ CustomizeMode.prototype = {
     if (aTargetArea == aOriginArea) {
       CustomizableUI.moveWidgetWithinArea(aDraggedItemId, position);
     } else {
       CustomizableUI.addWidgetToArea(aDraggedItemId, aTargetArea.id, position);
     }
 
     this._onDragEnd(aEvent);
 
-    // For BrowserUITelemetry, an "add" is only when we move an item from the palette
-    // into an area. Otherwise, it's a move.
-    let custEventType = aOriginArea.id == kPaletteId ? "add" : "move";
-    BrowserUITelemetry.countCustomizationEvent(custEventType);
-
     // If we dropped onto a skipintoolbarset item, manually correct the drop location:
     if (aTargetNode != itemForPlacement) {
       let draggedWrapper = draggedItem.parentNode;
       let container = draggedWrapper.parentNode;
       container.insertBefore(draggedWrapper, aTargetNode.parentNode);
     }
   },
 

--- a/browser/components/syncedtabs/TabListComponent.js
+++ b/browser/components/syncedtabs/TabListComponent.js
@@ -6,17 +6,16 @@
 
 ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 
 let log = ChromeUtils.import("resource://gre/modules/Log.jsm", {})
             .Log.repository.getLogger("Sync.RemoteTabs");
 
 XPCOMUtils.defineLazyModuleGetters(this, {
-  BrowserUITelemetry: "resource:///modules/BrowserUITelemetry.jsm",
   OpenInTabsUtils: "resource:///modules/OpenInTabsUtils.jsm",
 });
 
 var EXPORTED_SYMBOLS = [
   "TabListComponent"
 ];
 
 /**
@@ -109,17 +108,16 @@ TabListComponent.prototype = {
   onBookmarkTab(uri, title) {
     this._window.top.PlacesCommandHook
       .bookmarkLink(this._window.top.PlacesUtils.bookmarksMenuFolderId, uri, title)
       .catch(Cu.reportError);
   },
 
   onOpenTab(url, where, params) {
     this._window.openTrustedLinkIn(url, where, params);
-    BrowserUITelemetry.countSyncedTabEvent("open", "sidebar");
   },
 
   onOpenTabs(urls, where) {
     if (!OpenInTabsUtils.confirmOpenInTabs(urls.length, this._window)) {
       return;
     }
     if (where == "window") {
       this._window.openDialog(this._window.getBrowserURL(), "_blank",
@@ -127,17 +125,16 @@ TabListComponent.prototype = {
     } else {
       let loadInBackground = where == "tabshifted";
       this._getChromeWindow(this._window).gBrowser.loadTabs(urls, {
         inBackground: loadInBackground,
         replace: false,
         triggeringPrincipal: Services.scriptSecurityManager.getSystemPrincipal(),
       });
     }
-    BrowserUITelemetry.countSyncedTabEvent("openmultiple", "sidebar");
   },
 
   onCopyTabLocation(url) {
     this._clipboardHelper.copyString(url);
   },
 
   onSyncRefresh() {
     this._SyncedTabs.syncTabs(true);