Move the Widget hierarchy to the Oilpan heap.

Source/core/frame/RemoteFrame.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef RemoteFrame_h
 #define RemoteFrame_h
 
 #include "core/frame/Frame.h"
 
 namespace blink {
 
 class RemoteFrameView;
 
 class RemoteFrame: public Frame {
 public:
     static PassRefPtrWillBeRawPtr<RemoteFrame> create(FrameClient*, FrameHost*, FrameOwner*);
     virtual bool isRemoteFrame() const OVERRIDE { return true; }
 
     virtual ~RemoteFrame();
 
     virtual void detach() OVERRIDE;
 
-    void setView(PassRefPtr<RemoteFrameView>);
+    void setView(PassRefPtrWillBeRawPtr<RemoteFrameView>);
     void createView();
 
     RemoteFrameView* view() const;
 
+    void trace(Visitor*) OVERRIDE;
+
 private:
     RemoteFrame(FrameClient*, FrameHost*, FrameOwner*);
 
-    RefPtr<RemoteFrameView> m_view;
+    RefPtrWillBeMember<RemoteFrameView> m_view;
 };
 
 inline RemoteFrameView* RemoteFrame::view() const
 {
     return m_view.get();
 }
 
 DEFINE_TYPE_CASTS(RemoteFrame, Frame, remoteFrame, remoteFrame->isRemoteFrame(), remoteFrame.isRemoteFrame());
 
 } // namespace blink
 
 #endif // RemoteFrame_h