--- a/accessible/base/SelectionManager.h
+++ b/accessible/base/SelectionManager.h
@@ -116,17 +116,17 @@ protected:
 
   /**
    * Process DOM selection change. Fire selection and caret move events.
    */
   void ProcessSelectionChanged(SelData* aSelData);
 
 private:
   // Currently focused control.
-  AutoWeakFrame mCurrCtrlFrame;
+  WeakFrame mCurrCtrlFrame;
   int32_t mCaretOffset;
   HyperTextAccessible* mAccWithCaret;
 };
 
 } // namespace a11y
 } // namespace mozilla
 
 #endif

--- a/dom/base/nsFrameLoader.h
+++ b/dom/base/nsFrameLoader.h
@@ -324,17 +324,17 @@ private:
 
   // After the frameloader has been removed from the DOM but before all of the
   // messages from the frame have been received, we keep a strong reference to
   // our <browser> element.
   RefPtr<mozilla::dom::Element> mOwnerContentStrong;
 
   // Stores the root frame of the subdocument while the subdocument is being
   // reframed. Used to restore the presentation after reframing.
-  AutoWeakFrame mDetachedSubdocFrame;
+  WeakFrame mDetachedSubdocFrame;
   // Stores the containing document of the frame corresponding to this
   // frame loader. This is reference is kept valid while the subframe's
   // presentation is detached and stored in mDetachedSubdocFrame. This
   // enables us to detect whether the frame has moved documents during
   // a reframe, so that we know not to restore the presentation.
   nsCOMPtr<nsIDocument> mContainerDocWhileDetached;
 
   // An opener window which should be used when the docshell is created.

--- a/dom/base/nsObjectLoadingContent.h
+++ b/dom/base/nsObjectLoadingContent.h
@@ -710,16 +710,16 @@ class nsObjectLoadingContent : public ns
     // videos.
     bool                        mRewrittenYoutubeEmbed : 1;
 
     // Cache the answer of PreferFallback() because ShouldPlay is called several
     // times during the load process.
     bool                        mPreferFallback : 1;
     bool                        mPreferFallbackKnown : 1;
 
-    AutoWeakFrame                 mPrintFrame;
+    WeakFrame                   mPrintFrame;
 
     RefPtr<nsPluginInstanceOwner> mInstanceOwner;
     nsTArray<mozilla::dom::MozPluginParameter> mCachedAttributes;
     nsTArray<mozilla::dom::MozPluginParameter> mCachedParameters;
 };
 
 #endif

--- a/dom/events/EventStateManager.cpp
+++ b/dom/events/EventStateManager.cpp
@@ -4445,18 +4445,19 @@ EventStateManager::GenerateDragDropEnter
             WidgetDragEvent remoteEvent(aDragEvent->IsTrusted(), eDragExit,
                                         aDragEvent->mWidget);
             remoteEvent.AssignDragEventData(*aDragEvent, true);
             nsEventStatus remoteStatus = nsEventStatus_eIgnore;
             HandleCrossProcessEvent(&remoteEvent, &remoteStatus);
           }
         }
 
+        AutoWeakFrame currentTraget = mCurrentTarget;
         FireDragEnterOrExit(aPresContext, aDragEvent, eDragEnter,
-                            lastContent, targetContent, mCurrentTarget);
+                            lastContent, targetContent, currentTraget);
 
         if (sLastDragOverFrame) {
           FireDragEnterOrExit(sLastDragOverFrame->PresContext(),
                               aDragEvent, eDragLeave,
                               targetContent, lastContent, sLastDragOverFrame);
         }
 
         sLastDragOverFrame = mCurrentTarget;

--- a/dom/events/EventStateManager.h
+++ b/dom/events/EventStateManager.h
@@ -49,17 +49,17 @@ class OverOutElementsWrapper final : pub
   ~OverOutElementsWrapper();
 
 public:
   OverOutElementsWrapper();
 
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_CLASS(OverOutElementsWrapper)
 
-  AutoWeakFrame mLastOverFrame;
+  WeakFrame mLastOverFrame;
 
   nsCOMPtr<nsIContent> mLastOverElement;
 
   // The last element on which we fired a over event, or null if
   // the last over event we fired has finished processing.
   nsCOMPtr<nsIContent> mFirstOverEventElement;
 
   // The last element on which we fired a out event, or null if
@@ -925,17 +925,17 @@ private:
 
   // Stores the mRefPoint of the last synthetic mouse move we dispatched
   // to re-center the mouse when we were pointer locked. If this is (-1,-1) it
   // means we've not recently dispatched a centering event. We use this to
   // detect when we receive the synth event, so we can cancel and not send it
   // to content.
   static LayoutDeviceIntPoint sSynthCenteringPoint;
 
-  AutoWeakFrame mCurrentTarget;
+  WeakFrame mCurrentTarget;
   nsCOMPtr<nsIContent> mCurrentTargetContent;
   static AutoWeakFrame sLastDragOverFrame;
 
   // Stores the mRefPoint (the offset from the widget's origin in device
   // pixels) of the last mouse event.
   static LayoutDeviceIntPoint sLastRefPoint;
 
   // member variables for the d&d gesture state machine

--- a/layout/forms/nsComboboxControlFrame.cpp
+++ b/layout/forms/nsComboboxControlFrame.cpp
@@ -408,17 +408,17 @@ public:
   {
     if (mFrame.IsAlive()) {
       static_cast<nsComboboxControlFrame*>(mFrame.GetFrame())->
         AbsolutelyPositionDropDown();
     }
     return NS_OK;
   }
 
-  AutoWeakFrame mFrame;
+  WeakFrame mFrame;
 };
 
 void
 nsComboboxControlFrame::ReflowDropdown(nsPresContext*  aPresContext,
                                        const ReflowInput& aReflowInput)
 {
   // All we want out of it later on, really, is the block size of a row, so we
   // don't even need to cache mDropdownFrame's ascent or anything.  If we don't
@@ -522,17 +522,17 @@ public:
   NS_IMETHOD Run() override
   {
     if (mFrame.IsAlive()) {
       static_cast<nsComboboxControlFrame*>(mFrame.GetFrame())
         ->RollupFromList();
     }
     return NS_OK;
   }
-  AutoWeakFrame mFrame;
+  WeakFrame mFrame;
 };
 
 class nsAsyncResize : public Runnable
 {
 public:
   explicit nsAsyncResize(nsComboboxControlFrame* aFrame) : mFrame(aFrame) {}
   NS_IMETHOD Run() override
   {
@@ -551,17 +551,17 @@ public:
           SetSuppressScrollbarUpdate(false);
         if (combo->mDelayedShowDropDown) {
           combo->ShowDropDown(true);
         }
       }
     }
     return NS_OK;
   }
-  AutoWeakFrame mFrame;
+  WeakFrame mFrame;
 };
 
 void
 nsComboboxControlFrame::GetAvailableDropdownSpace(WritingMode aWM,
                                                   nscoord* aBefore,
                                                   nscoord* aAfter,
                                                   LogicalPoint* aTranslation)
 {

--- a/layout/forms/nsDateTimeControlFrame.h
+++ b/layout/forms/nsDateTimeControlFrame.h
@@ -98,17 +98,17 @@ private:
         static_cast<nsDateTimeControlFrame*>(mFrame.GetFrame());
       NS_ENSURE_STATE(frame);
 
       frame->SyncDisabledState();
       return NS_OK;
     }
 
   private:
-    AutoWeakFrame mFrame;
+    WeakFrame mFrame;
   };
 
   /**
    * Sync the disabled state of the anonymous children up with our content's.
    */
   void SyncDisabledState();
 
   // Anonymous child which is bound via XBL to an element that wraps the input

--- a/layout/forms/nsFileControlFrame.h
+++ b/layout/forms/nsFileControlFrame.h
@@ -106,17 +106,17 @@ protected:
       nsFileControlFrame* frame = static_cast<nsFileControlFrame*>(mFrame.GetFrame());
       NS_ENSURE_STATE(frame);
 
       frame->SyncDisabledState();
       return NS_OK;
     }
 
   private:
-    AutoWeakFrame mFrame;
+    WeakFrame mFrame;
   };
 
   class DnDListener: public MouseListener {
   public:
     explicit DnDListener(nsFileControlFrame* aFrame)
       : MouseListener(aFrame)
     {}
 

--- a/layout/forms/nsNumberControlFrame.h
+++ b/layout/forms/nsNumberControlFrame.h
@@ -187,17 +187,17 @@ private:
         static_cast<nsNumberControlFrame*>(mFrame.GetFrame());
       NS_ENSURE_STATE(frame);
 
       frame->SyncDisabledState();
       return NS_OK;
     }
 
   private:
-    AutoWeakFrame mFrame;
+    WeakFrame mFrame;
   };
 
   /**
    * Sync the disabled state of the anonymous children up with our content's.
    */
   void SyncDisabledState();
 
   /**

--- a/layout/generic/nsSubDocumentFrame.cpp
+++ b/layout/generic/nsSubDocumentFrame.cpp
@@ -88,17 +88,17 @@ public:
   {
     PROFILER_LABEL("mozilla", "AsyncFrameInit::Run", js::ProfileEntry::Category::OTHER);
     if (mFrame.IsAlive()) {
       static_cast<nsSubDocumentFrame*>(mFrame.GetFrame())->ShowViewer();
     }
     return NS_OK;
   }
 private:
-  AutoWeakFrame mFrame;
+  WeakFrame mFrame;
 };
 
 static void
 InsertViewsInReverseOrder(nsView* aSibling, nsView* aParent);
 
 static void
 EndSwapDocShellsForViews(nsView* aView);
 

--- a/layout/painting/ActiveLayerTracker.cpp
+++ b/layout/painting/ActiveLayerTracker.cpp
@@ -100,17 +100,17 @@ public:
 
   nsExpirationState mState;
 
   // Previous scale due to the CSS transform property.
   Maybe<gfxSize> mPreviousTransformScale;
 
   // The scroll frame during for which we most recently received a call to
   // NotifyAnimatedFromScrollHandler.
-  AutoWeakFrame mAnimatingScrollHandlerFrame;
+  WeakFrame mAnimatingScrollHandlerFrame;
   // The set of activities that were triggered during
   // mAnimatingScrollHandlerFrame's scroll event handler.
   EnumSet<ActivityIndex> mScrollHandlerInducedActivity;
 
   // Number of restyle operations detected
   uint8_t mRestyleCounts[ACTIVITY_COUNT];
   bool mContentActive;
 };
@@ -127,17 +127,17 @@ public:
   ~LayerActivityTracker() {
     mDestroying = true;
     AgeAllGenerations();
   }
 
   virtual void NotifyExpired(LayerActivity* aObject);
 
 public:
-  AutoWeakFrame mCurrentScrollHandlerFrame;
+  WeakFrame mCurrentScrollHandlerFrame;
 
 private:
   bool mDestroying;
 };
 
 static LayerActivityTracker* gLayerActivityTracker = nullptr;
 
 LayerActivity::~LayerActivity()

--- a/layout/printing/nsPrintEngine.h
+++ b/layout/printing/nsPrintEngine.h
@@ -258,17 +258,17 @@ protected:
   bool mProgressDialogIsShown;
 
   nsCOMPtr<nsIDocumentViewerPrint> mDocViewerPrint;
   nsWeakPtr               mContainer;
   float                   mScreenDPI;
   
   mozilla::UniquePtr<nsPrintData> mPrt;
   nsPagePrintTimer*       mPagePrintTimer;
-  AutoWeakFrame             mPageSeqFrame;
+  WeakFrame               mPageSeqFrame;
 
   // Print Preview
   mozilla::UniquePtr<nsPrintData> mPrtPreview;
   mozilla::UniquePtr<nsPrintData> mOldPrtPreview;
 
   nsCOMPtr<nsIDocument>   mDocument;
 
   FILE* mDebugFile;

--- a/layout/tables/nsTableFrame.cpp
+++ b/layout/tables/nsTableFrame.cpp
@@ -4856,17 +4856,17 @@ public:
       nsTableFrame* tableFrame = static_cast <nsTableFrame*>(mFrame.GetFrame());
       if (tableFrame->NeedToCalcBCBorders()) {
         tableFrame->CalcBCBorders();
       }
     }
     return NS_OK;
   }
 private:
-  AutoWeakFrame mFrame;
+  WeakFrame mFrame;
 };
 
 bool
 nsTableFrame::BCRecalcNeeded(nsStyleContext* aOldStyleContext,
                              nsStyleContext* aNewStyleContext)
 {
   // Attention: the old style context is the one we're forgetting,
   // and hence possibly completely bogus for GetStyle* purposes.

--- a/layout/xul/nsListBoxBodyFrame.cpp
+++ b/layout/xul/nsListBoxBodyFrame.cpp
@@ -1125,25 +1125,25 @@ nsListBoxBodyFrame::GetFirstItemBox(int3
 {
   if (aCreated)
    *aCreated = false;
 
   // Clear ourselves out.
   mBottomFrame = mTopFrame;
 
   if (mTopFrame) {
-    return mTopFrame->IsXULBoxFrame() ? mTopFrame : nullptr;
+    return mTopFrame->IsXULBoxFrame() ? mTopFrame.GetFrame() : nullptr;
   }
 
   // top frame was cleared out
   mTopFrame = GetFirstFrame();
   mBottomFrame = mTopFrame;
 
   if (mTopFrame && mRowsToPrepend <= 0) {
-    return mTopFrame->IsXULBoxFrame() ? mTopFrame : nullptr;
+    return mTopFrame->IsXULBoxFrame() ? mTopFrame.GetFrame() : nullptr;
   }
 
   // At this point, we either have no frames at all, 
   // or the user has scrolled upwards, leaving frames
   // to be created at the top.  Let's determine which
   // content needs a new frame first.
 
   nsCOMPtr<nsIContent> startContent;
@@ -1182,17 +1182,17 @@ nsListBoxBodyFrame::GetFirstItemBox(int3
     fc->CreateListBoxContent(this, nullptr, startContent, &topFrame, isAppend);
     mTopFrame = topFrame;
     if (mTopFrame) {
       if (aCreated)
         *aCreated = true;
 
       mBottomFrame = mTopFrame;
 
-      return mTopFrame->IsXULBoxFrame() ? mTopFrame : nullptr;
+      return mTopFrame->IsXULBoxFrame() ? mTopFrame.GetFrame() : nullptr;
     } else
       return GetFirstItemBox(++aOffset, 0);
   }
 
   return nullptr;
 }
 
 //

--- a/layout/xul/nsListBoxBodyFrame.h
+++ b/layout/xul/nsListBoxBodyFrame.h
@@ -180,17 +180,17 @@ protected:
   void ComputeTotalRowCount();
   int32_t ToRowIndex(nscoord aPos) const;
   void RemoveChildFrame(nsBoxLayoutState &aState, nsIFrame *aChild);
 
   nsTArray< RefPtr<nsPositionChangedEvent> > mPendingPositionChangeEvents;
   nsCOMPtr<nsPIBoxObject> mBoxObject;
 
   // frame markers
-  AutoWeakFrame mTopFrame;
+  WeakFrame mTopFrame;
   nsIFrame* mBottomFrame;
   nsIFrame* mLinkupFrame;
 
   nsListScrollSmoother* mScrollSmoother;
 
   int32_t mRowsToPrepend;
 
   // row height

--- a/layout/xul/nsMenuFrame.cpp
+++ b/layout/xul/nsMenuFrame.cpp
@@ -133,17 +133,17 @@ public:
     else if (mAttr == nsGkAtoms::key) {
       frame->BuildAcceleratorText(true);
     } else if (mAttr == nsGkAtoms::type || mAttr == nsGkAtoms::name) {
       frame->UpdateMenuType();
     }
     return NS_OK;
   }
 protected:
-  AutoWeakFrame       mFrame;
+  WeakFrame         mFrame;
   nsCOMPtr<nsIAtom> mAttr;
 };
 
 //
 // NS_NewMenuFrame and NS_NewMenuItemFrame
 //
 // Wrappers for creating a new menu popup container
 //

--- a/layout/xul/nsProgressMeterFrame.cpp
+++ b/layout/xul/nsProgressMeterFrame.cpp
@@ -26,17 +26,17 @@ class nsReflowFrameRunnable : public moz
 {
 public:
   nsReflowFrameRunnable(nsIFrame* aFrame,
                         nsIPresShell::IntrinsicDirty aIntrinsicDirty,
                         nsFrameState aBitToAdd);
 
   NS_DECL_NSIRUNNABLE
 
-  AutoWeakFrame mWeakFrame;
+  WeakFrame mWeakFrame;
   nsIPresShell::IntrinsicDirty mIntrinsicDirty;
   nsFrameState mBitToAdd;
 };
 
 nsReflowFrameRunnable::nsReflowFrameRunnable(nsIFrame* aFrame,
                           nsIPresShell::IntrinsicDirty aIntrinsicDirty,
                           nsFrameState aBitToAdd)
   : mWeakFrame(aFrame),
@@ -95,17 +95,17 @@ public:
     return shouldFlush;
   }
 
   virtual void ReflowCallbackCanceled() override
   {
     delete this;
   }
 
-  AutoWeakFrame mWeakFrame;
+  WeakFrame mWeakFrame;
 };
 
 NS_IMETHODIMP
 nsProgressMeterFrame::DoXULLayout(nsBoxLayoutState& aState)
 {
   if (mNeedsReflowCallback) {
     nsIReflowCallback* cb = new nsAsyncProgressMeterInit(this);
     if (cb) {

--- a/layout/xul/nsTextBoxFrame.cpp
+++ b/layout/xul/nsTextBoxFrame.cpp
@@ -182,21 +182,21 @@ public:
         return shouldFlush;
     }
 
     virtual void ReflowCallbackCanceled() override
     {
         delete this;
     }
 
-    AutoWeakFrame mWeakFrame;
+    WeakFrame mWeakFrame;
 };
 
 bool
-nsTextBoxFrame::UpdateAccesskey(AutoWeakFrame& aWeakThis)
+nsTextBoxFrame::UpdateAccesskey(WeakFrame& aWeakThis)
 {
     nsAutoString accesskey;
     nsCOMPtr<nsIDOMXULLabelElement> labelElement = do_QueryInterface(mContent);
     NS_ENSURE_TRUE(aWeakThis.IsAlive(), false);
     if (labelElement) {
         // Accesskey may be stored on control.
         labelElement->GetAccessKey(accesskey);
         NS_ENSURE_TRUE(aWeakThis.IsAlive(), false);

--- a/layout/xul/nsTextBoxFrame.h
+++ b/layout/xul/nsTextBoxFrame.h
@@ -66,17 +66,17 @@ public:
 
   virtual void DidSetStyleContext(nsStyleContext* aOldStyleContext) override;
 
 protected:
   friend class nsAsyncAccesskeyUpdate;
   friend class nsDisplayXULTextBox;
   // Should be called only by nsAsyncAccesskeyUpdate.
   // Returns true if accesskey was updated.
-  bool UpdateAccesskey(AutoWeakFrame& aWeakThis);
+  bool UpdateAccesskey(WeakFrame& aWeakThis);
   void UpdateAccessTitle();
   void UpdateAccessIndex();
 
   // Recompute our title, ignoring the access key but taking into
   // account text-transform.
   void RecomputeTitle();
 
   // REVIEW: SORRY! Couldn't resist devirtualizing these

--- a/layout/xul/nsXULPopupManager.cpp
+++ b/layout/xul/nsXULPopupManager.cpp
@@ -1258,22 +1258,21 @@ nsXULPopupManager::HidePopupAfterDelay(n
   // is set to mTimerMenu, so it should be safe to keep a reference to it
   mTimerMenu = aPopup;
 }
 
 void
 nsXULPopupManager::HidePopupsInList(const nsTArray<nsMenuPopupFrame *> &aFrames)
 {
   // Create a weak frame list. This is done in a separate array with the
-  // right capacity predetermined, otherwise the array would get resized and
-  // move the weak frame pointers around.
-  nsTArray<AutoWeakFrame> weakPopups(aFrames.Length());
+  // right capacity predetermined to avoid multiple allocations.
+  nsTArray<WeakFrame> weakPopups(aFrames.Length());
   uint32_t f;
   for (f = 0; f < aFrames.Length(); f++) {
-    AutoWeakFrame* wframe = weakPopups.AppendElement();
+    WeakFrame* wframe = weakPopups.AppendElement();
     if (wframe)
       *wframe = aFrames[f];
   }
 
   for (f = 0; f < weakPopups.Length(); f++) {
     // check to ensure that the frame is still alive before hiding it.
     if (weakPopups[f].IsAlive()) {
       nsMenuPopupFrame* frame =

--- a/layout/xul/tree/nsTreeBodyFrame.cpp
+++ b/layout/xul/tree/nsTreeBodyFrame.cpp
@@ -4901,17 +4901,17 @@ public:
     if (mFrame.IsAlive()) {
       nsTreeBodyFrame* tree = static_cast<nsTreeBodyFrame*>(mFrame.GetFrame());
       nsTreeBodyFrame::ScrollParts parts = tree->GetScrollParts();
       tree->CheckOverflow(parts);
     }
     return NS_OK;
   }
 private:
-  AutoWeakFrame mFrame;
+  WeakFrame mFrame;
 };
 
 bool
 nsTreeBodyFrame::FullScrollbarsUpdate(bool aNeedsFullInvalidation)
 {
   ScrollParts parts = GetScrollParts();
   AutoWeakFrame weakFrame(this);
   AutoWeakFrame weakColumnsFrame(parts.mColumnsFrame);