Add a pure virtual method to the GarbageCollectedMixin class

Source/core/frame/LocalFrame.h

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999-2001 Lars Knoll <knoll@kde.org>
  *                     1999-2001 Antti Koivisto <koivisto@kde.org>
  *                     2000-2001 Simon Hausmann <hausmann@kde.org>
  *                     2000-2001 Dirk Mueller <mueller@kde.org>
  *                     2000 Stefan Schimanski <1Stein@gmx.de>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
@@ skipping 46 matching lines @@
     class IntSize;
     class Node;
     class Range;
     class RenderView;
     class TreeScope;
     class ScriptController;
     class SpellChecker;
     class TreeScope;
     class VisiblePosition;
 
-    class LocalFrame : public Frame, public WillBeHeapSupplementable<LocalFrame>  {
+    class LocalFrame : public Frame, public WillBeHeapSupplementable<LocalFrame> {
+        WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(LocalFrame);
     public:
         static PassRefPtrWillBeRawPtr<LocalFrame> create(FrameLoaderClient*, FrameHost*, FrameOwner*);
 
         virtual bool isLocalFrame() const override { return true; }
 
         void init();
         void setView(PassRefPtrWillBeRawPtr<FrameView>);
         void createView(const IntSize&, const Color&, bool,
             ScrollbarMode = ScrollbarAuto, bool horizontalLock = false,
             ScrollbarMode = ScrollbarAuto, bool verticalLock = false);
@@ skipping 203 matching lines @@
     DEFINE_TYPE_CASTS(LocalFrame, Frame, localFrame, localFrame->isLocalFrame(), localFrame.isLocalFrame());
 
 } // namespace blink
 
 // During refactoring, there are some places where we need to do type conversions that
 // will not be needed once all instances of LocalFrame and RemoteFrame are sorted out.
 // At that time this #define will be removed and all the uses of it will need to be corrected.
 #define toLocalFrameTemporary toLocalFrame
 
 #endif // LocalFrame_h