--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -99,17 +99,16 @@
 #include "nsIWidget.h"
 #include "nsIWidgetListener.h"
 #include "nsIBaseWindow.h"
 #include "nsIDeviceSensors.h"
 #include "nsIContent.h"
 #include "nsIDocShell.h"
 #include "nsIDocCharset.h"
 #include "nsIDocument.h"
-#include "nsIDocumentInlines.h"
 #include "Crypto.h"
 #include "nsIDOMDocument.h"
 #include "nsIDOMElement.h"
 #include "nsIDOMEvent.h"
 #include "nsIDOMOfflineResourceList.h"
 #include "nsDOMString.h"
 #include "nsIEmbeddingSiteWindow.h"
 #include "nsThreadUtils.h"
@@ -995,17 +994,16 @@ NextWindowID();
 
 template<class T>
 nsPIDOMWindow<T>::nsPIDOMWindow(nsPIDOMWindowOuter *aOuterWindow)
 : mFrameElement(nullptr), mDocShell(nullptr), mModalStateDepth(0),
   mMutationBits(0), mIsDocumentLoaded(false),
   mIsHandlingResizeEvent(false), mIsInnerWindow(aOuterWindow != nullptr),
   mMayHavePaintEventListener(false), mMayHaveTouchEventListener(false),
   mMayHaveMouseEnterLeaveEventListener(false),
-  mMayHaveMouseMoveEventListener(false),
   mMayHavePointerEnterLeaveEventListener(false),
   mInnerObjectsFreed(false),
   mIsModalContentWindow(false),
   mIsActive(false), mIsBackground(false),
   mMediaSuspend(Preferences::GetBool("media.block-autoplay-until-in-foreground", true) ?
     nsISuspendedTypes::SUSPENDED_BLOCK : nsISuspendedTypes::NONE_SUSPENDED),
   mAudioMuted(false), mAudioVolume(1.0), mAudioCaptured(false),
   mDesktopModeViewport(false), mIsRootOuterWindow(false), mInnerWindow(nullptr),
@@ -2077,33 +2075,16 @@ nsGlobalWindow::ClearControllers()
   }
 }
 
 void
 nsGlobalWindow::FreeInnerObjects()
 {
   NS_ASSERTION(IsInnerWindow(), "Don't free inner objects on an outer window");
 
-  if (mDoc && !nsContentUtils::IsSystemPrincipal(mDoc->NodePrincipal())) {
-    EventTarget* win = this;
-    EventTarget* html = mDoc->GetHtmlElement();
-    EventTarget* body = mDoc->GetBodyElement();
-
-    bool mouseAware = AsInner()->HasMouseMoveEventListeners();
-    bool keyboardAware = win->MayHaveAPZAwareKeyEventListener() ||
-                         mDoc->MayHaveAPZAwareKeyEventListener() ||
-                         (html && html->MayHaveAPZAwareKeyEventListener()) ||
-                         (body && body->MayHaveAPZAwareKeyEventListener());
-
-    Telemetry::Accumulate(Telemetry::APZ_AWARE_MOUSEMOVE_LISTENERS,
-                          mouseAware ? 1 : 0);
-    Telemetry::Accumulate(Telemetry::APZ_AWARE_KEY_LISTENERS,
-                          keyboardAware ? 1 : 0);
-  }
-
   // Make sure that this is called before we null out the document and
   // other members that the window destroyed observers could
   // re-create.
   NotifyDOMWindowDestroyed(this);
   if (auto* reporter = nsWindowMemoryReporter::Get()) {
     reporter->ObserveDOMWindowDetached(this);
   }
 

--- a/dom/base/nsNodeUtils.cpp
+++ b/dom/base/nsNodeUtils.cpp
@@ -534,19 +534,16 @@ nsNodeUtils::CloneAndAdopt(nsINode *aNod
         if (elm) {
           window->SetMutationListeners(elm->MutationListenerBits());
           if (elm->MayHavePaintEventListener()) {
             window->SetHasPaintEventListeners();
           }
           if (elm->MayHaveTouchEventListener()) {
             window->SetHasTouchEventListeners();
           }
-          if (elm->MayHaveMouseMoveEventListener()) {
-            window->SetHasMouseMoveEventListeners();
-          }
           if (elm->MayHaveMouseEnterLeaveEventListener()) {
             window->SetHasMouseEnterLeaveEventListeners();
           }
           if (elm->MayHavePointerEnterLeaveEventListener()) {
             window->SetHasPointerEnterLeaveEventListeners();
           }
         }
       }

--- a/dom/base/nsPIDOMWindow.h
+++ b/dom/base/nsPIDOMWindow.h
@@ -663,17 +663,16 @@ protected:
   uint32_t               mMutationBits;
 
   bool                   mIsDocumentLoaded;
   bool                   mIsHandlingResizeEvent;
   bool                   mIsInnerWindow;
   bool                   mMayHavePaintEventListener;
   bool                   mMayHaveTouchEventListener;
   bool                   mMayHaveMouseEnterLeaveEventListener;
-  bool                   mMayHaveMouseMoveEventListener;
   bool                   mMayHavePointerEnterLeaveEventListener;
 
   // Used to detect whether we have called FreeInnerObjects() (e.g. to ensure
   // that a call to ResumeTimeouts() after FreeInnerObjects() does nothing).
   // This member is only used by inner windows.
   bool                   mInnerObjectsFreed;
 
 
@@ -811,34 +810,16 @@ public:
       return;
     }
 
     mMutationBits |= aType;
   }
 
   /**
    * Call this to check whether some node (this window, its document,
-   * or content in that document) has or had a mousemove event listener.
-   */
-  bool HasMouseMoveEventListeners()
-  {
-    return mMayHaveMouseMoveEventListener;
-  }
-
-  /**
-   * Call this to indicate that some node (this window, its document,
-   * or content in that document) has or had a mousemove event listener.
-   */
-  void SetHasMouseMoveEventListeners()
-  {
-    mMayHaveMouseMoveEventListener = true;
-  }
-
-  /**
-   * Call this to check whether some node (this window, its document,
    * or content in that document) has a mouseenter/leave event listener.
    */
   bool HasMouseEnterLeaveEventListeners()
   {
     return mMayHaveMouseEnterLeaveEventListener;
   }
 
   /**

--- a/dom/events/EventListenerManager.cpp
+++ b/dom/events/EventListenerManager.cpp
@@ -121,20 +121,18 @@ IsWebkitPrefixSupportEnabled()
 
 EventListenerManagerBase::EventListenerManagerBase()
   : mNoListenerForEvent(eVoidEvent)
   , mMayHavePaintEventListener(false)
   , mMayHaveMutationListeners(false)
   , mMayHaveCapturingListeners(false)
   , mMayHaveSystemGroupListeners(false)
   , mMayHaveTouchEventListener(false)
-  , mMayHaveMouseMoveEventListener(false)
   , mMayHaveMouseEnterLeaveEventListener(false)
   , mMayHavePointerEnterLeaveEventListener(false)
-  , mMayHaveAPZAwareKeyEventListener(false)
   , mMayHaveKeyEventListener(false)
   , mMayHaveInputOrCompositionEventListener(false)
   , mClearingListeners(false)
   , mIsMainThreadELM(NS_IsMainThread())
 {
   static_assert(sizeof(EventListenerManagerBase) == sizeof(uint32_t),
                 "Keep the size of EventListenerManagerBase size compact!");
 }
@@ -407,31 +405,23 @@ EventListenerManager::AddEventListenerIn
       window->SetHasGamepadEventListener();
     }
   } else if (aTypeAtom == nsGkAtoms::onkeydown ||
              aTypeAtom == nsGkAtoms::onkeypress ||
              aTypeAtom == nsGkAtoms::onkeyup) {
     if (!aFlags.mInSystemGroup) {
       mMayHaveKeyEventListener = true;
     }
-    if (!aFlags.mPassive && aTypeAtom != nsGkAtoms::onkeyup) {
-      mMayHaveAPZAwareKeyEventListener = true;
-    }
   } else if (aTypeAtom == nsGkAtoms::oncompositionend ||
              aTypeAtom == nsGkAtoms::oncompositionstart ||
              aTypeAtom == nsGkAtoms::oncompositionupdate ||
              aTypeAtom == nsGkAtoms::oninput) {
     if (!aFlags.mInSystemGroup) {
       mMayHaveInputOrCompositionEventListener = true;
     }
-  } else if (aTypeAtom == nsGkAtoms::onmousemove) {
-    mMayHaveMouseMoveEventListener = true;
-    if (nsPIDOMWindowInner* window = GetInnerWindowForTarget()) {
-      window->SetHasMouseMoveEventListeners();
-    }
   }
 
   if (IsApzAwareListener(listener)) {
     ProcessApzAwareEventListenerAdd();
   }
 
   if (mTarget) {
     if (aTypeAtom) {

--- a/dom/events/EventListenerManager.h
+++ b/dom/events/EventListenerManager.h
@@ -156,25 +156,23 @@ protected:
   EventListenerManagerBase();
 
   EventMessage mNoListenerForEvent;
   uint16_t mMayHavePaintEventListener : 1;
   uint16_t mMayHaveMutationListeners : 1;
   uint16_t mMayHaveCapturingListeners : 1;
   uint16_t mMayHaveSystemGroupListeners : 1;
   uint16_t mMayHaveTouchEventListener : 1;
-  uint16_t mMayHaveMouseMoveEventListener : 1;
   uint16_t mMayHaveMouseEnterLeaveEventListener : 1;
   uint16_t mMayHavePointerEnterLeaveEventListener : 1;
-  uint16_t mMayHaveAPZAwareKeyEventListener : 1;
   uint16_t mMayHaveKeyEventListener : 1;
   uint16_t mMayHaveInputOrCompositionEventListener : 1;
   uint16_t mClearingListeners : 1;
   uint16_t mIsMainThreadELM : 1;
-  // uint16_t mUnused : 3;
+  // uint16_t mUnused : 5;
 };
 
 /*
  * Event listener manager
  */
 
 class EventListenerManager final : public EventListenerManagerBase
 {
@@ -436,23 +434,19 @@ public:
   bool MayHavePaintEventListener() { return mMayHavePaintEventListener; }
 
   /**
    * Returns true if there may be a touch event listener registered,
    * false if there definitely isn't.
    */
   bool MayHaveTouchEventListener() { return mMayHaveTouchEventListener; }
 
-  bool MayHaveMouseMoveEventListener() { return mMayHaveMouseMoveEventListener; }
-
   bool MayHaveMouseEnterLeaveEventListener() { return mMayHaveMouseEnterLeaveEventListener; }
   bool MayHavePointerEnterLeaveEventListener() { return mMayHavePointerEnterLeaveEventListener; }
 
-  bool MayHaveAPZAwareKeyEventListener() const { return mMayHaveAPZAwareKeyEventListener; }
-
   /**
    * Returns true if there may be a key event listener (keydown, keypress,
    * or keyup) registered, or false if there definitely isn't.
    */
   bool MayHaveKeyEventListener() { return mMayHaveKeyEventListener; }
 
   /**
    * Returns true if there may be an advanced input event listener (input,

--- a/dom/events/EventTarget.cpp
+++ b/dom/events/EventTarget.cpp
@@ -60,23 +60,16 @@ EventTarget::SetEventHandler(nsIAtom* aT
 bool
 EventTarget::IsApzAware() const
 {
   EventListenerManager* elm = GetExistingListenerManager();
   return elm && elm->HasApzAwareListeners();
 }
 
 bool
-EventTarget::MayHaveAPZAwareKeyEventListener() const
-{
-  EventListenerManager* elm = GetExistingListenerManager();
-  return elm && elm->MayHaveAPZAwareKeyEventListener();
-}
-
-bool
 EventTarget::DispatchEvent(Event& aEvent,
                            CallerType aCallerType,
                            ErrorResult& aRv)
 {
   bool result = false;
   aRv = DispatchEvent(&aEvent, &result);
   return !aEvent.DefaultPrevented(aCallerType);
 }

--- a/dom/events/EventTarget.h
+++ b/dom/events/EventTarget.h
@@ -95,17 +95,16 @@ public:
    * exist.
    */
   virtual EventListenerManager* GetExistingListenerManager() const = 0;
 
   // Called from AsyncEventDispatcher to notify it is running.
   virtual void AsyncEventRunning(AsyncEventDispatcher* aEvent) {}
 
   virtual bool IsApzAware() const;
-  bool MayHaveAPZAwareKeyEventListener() const;
 
 protected:
   EventHandlerNonNull* GetEventHandler(nsIAtom* aType,
                                        const nsAString& aTypeString);
   void SetEventHandler(nsIAtom* aType, const nsAString& aTypeString,
                        EventHandlerNonNull* aHandler);
 };
 

--- a/toolkit/components/telemetry/Histograms.json
+++ b/toolkit/components/telemetry/Histograms.json
@@ -12195,32 +12195,16 @@
   "GFX_CRASH": {
     "record_in_processes": ["main", "content"],
     "expires_in_version": "never",
     "kind": "enumerated",
     "n_values": 100,
     "releaseChannelCollection": "opt-out",
     "description": "Graphics Crash Reason (...)"
   },
-  "APZ_AWARE_KEY_LISTENERS": {
-    "record_in_processes": ["main", "content"],
-    "alert_emails": ["rhunt@mozilla.com"],
-    "bug_numbers": [1352654],
-    "expires_in_version": "58",
-    "kind": "boolean",
-    "description": "The percentage of pages with a non-passive key event on the path to the root scrolling element that would disable APZ key scrolling. This is tracked for non system principal windows, so it applies to toplevel windows and subframes/iframes, but not chrome windows. "
-  },
-  "APZ_AWARE_MOUSEMOVE_LISTENERS": {
-    "record_in_processes": ["main", "content"],
-    "alert_emails": ["rhunt@mozilla.com"],
-    "bug_numbers": [1352654],
-    "expires_in_version": "58",
-    "kind": "boolean",
-    "description": "The percentage of pages with a mousemove listener anywhere in the document that would disable APZ key scrolling. This is tracked for non system principal windows, so it applies to toplevel windows and subframes/iframes, but not chrome windows."
-  },
   "SCROLL_INPUT_METHODS": {
     "record_in_processes": ["main", "content", "gpu"],
     "alert_emails": ["botond@mozilla.com"],
     "bug_numbers": [1238137],
     "expires_in_version": "60",
     "kind": "enumerated",
     "n_values": 64,
     "description": "Count of scroll actions triggered by different input methods. See gfx/layers/apz/util/ScrollInputMethods.h for a list of possible values and their meanings."