Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/core/page/Page.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 13 matching lines @@
 #include "core/dom/ViewportDescription.h"
 #include "core/frame/SettingsDelegate.h"
 #include "core/frame/UseCounter.h"
 #include "core/page/HistoryController.h"
 #include "core/page/PageAnimator.h"
 #include "core/page/PageVisibilityState.h"
 #include "platform/LifecycleContext.h"
 #include "platform/Supplementable.h"
 #include "platform/geometry/LayoutRect.h"
 #include "platform/geometry/Region.h"
+#include "platform/heap/Handle.h"
 #include "wtf/Forward.h"
 #include "wtf/HashSet.h"
 #include "wtf/Noncopyable.h"
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
 class AutoscrollController;
 class BackForwardClient;
 class Chrome;
@@ skipping 155 matching lines @@
     bool isCursorVisible() const { return m_isCursorVisible; }
     void setIsCursorVisible(bool isVisible) { m_isCursorVisible = isVisible; }
 
 #ifndef NDEBUG
     void setIsPainting(bool painting) { m_isPainting = painting; }
     bool isPainting() const { return m_isPainting; }
 #endif
 
     double timerAlignmentInterval() const;
 
-    class MultisamplingChangedObserver {
+    class MultisamplingChangedObserver : public WillBeGarbageCollectedMixin {
     public:
         virtual void multisamplingChanged(bool) = 0;
     };
 
     void addMultisamplingChangedObserver(MultisamplingChangedObserver*);
     void removeMultisamplingChangedObserver(MultisamplingChangedObserver*);
 
     void didCommitLoad(LocalFrame*);
 
     static void networkStateChanged(bool online);
     PassOwnPtr<LifecycleNotifier<Page> > createLifecycleNotifier();
 
     virtual void trace(Visitor*);
-
+    void clearWeakMembers(Visitor*);
     void willBeDestroyed();
 
 protected:
     PageLifecycleNotifier& lifecycleNotifier();
 
 private:
     void initGroup();
 
 #if ASSERT_DISABLED
     void checkSubframeCountConsistency() const { }
@@ skipping 48 matching lines @@
     double m_timerAlignmentInterval;
 
     PageVisibilityState m_visibilityState;
 
     bool m_isCursorVisible;
 
 #ifndef NDEBUG
     bool m_isPainting;
 #endif
 
-    HashSet<MultisamplingChangedObserver*> m_multisamplingChangedObservers;
+    WillBeHeapHashSet<RawPtrWillBeWeakMember<MultisamplingChangedObserver> > m_multisamplingChangedObservers;
 
     // A pointer to all the interfaces provided to in-process Frames for this Page.
     // FIXME: Most of the members of Page should move onto FrameHost.
     OwnPtr<FrameHost> m_frameHost;
 };
 
 } // namespace WebCore
 
 #endif // Page_h