Move Frame pointer to be held by DOMWindow base class.

third_party/WebKit/Source/core/frame/RemoteDOMWindow.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 RemoteDOMWindow_h
 #define RemoteDOMWindow_h
 
 #include "core/frame/DOMWindow.h"
 #include "core/frame/RemoteFrame.h"
 #include "wtf/Assertions.h"
 
 namespace blink {
 
 class RemoteDOMWindow final : public DOMWindow {
  public:
   static RemoteDOMWindow* create(RemoteFrame& frame) {
     return new RemoteDOMWindow(frame);
   }
 
+  RemoteFrame* frame() const { return toRemoteFrame(DOMWindow::frame()); }
+
   // EventTarget overrides:
   ExecutionContext* getExecutionContext() const override;
 
   // DOMWindow overrides:
   DECLARE_VIRTUAL_TRACE();
-  RemoteFrame* frame() const override;
   Screen* screen() const override;
   History* history() const override;
   BarProp* locationbar() const override;
   BarProp* menubar() const override;
   BarProp* personalbar() const override;
   BarProp* scrollbars() const override;
   BarProp* statusbar() const override;
   BarProp* toolbar() const override;
   Navigator* navigator() const override;
   bool offscreenBuffering() const override;
@@ skipping 63 matching lines @@
                            PassRefPtr<SecurityOrigin> target,
                            Document* source) override;
 
  private:
   explicit RemoteDOMWindow(RemoteFrame&);
 
   // Intentionally private to prevent redundant checks when the type is
   // already RemoteDOMWindow.
   bool isLocalDOMWindow() const override { return false; }
   bool isRemoteDOMWindow() const override { return true; }
-
-  Member<RemoteFrame> m_frame;
 };
 
 DEFINE_TYPE_CASTS(RemoteDOMWindow,
                   DOMWindow,
                   x,
                   x->isRemoteDOMWindow(),
                   x.isRemoteDOMWindow());
 
 }  // namespace blink
 
 #endif  // DOMWindow_h