Add a basic DOMWindow base class and use it in WindowProxy.

Source/core/frame/RemoteFrame.cpp

 // 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.
 
 #include "config.h"
 #include "core/frame/RemoteFrame.h"
 
 #include "core/frame/RemoteFrameClient.h"
 #include "core/frame/RemoteFrameView.h"
 #include "core/html/HTMLFrameOwnerElement.h"
 #include "platform/weborigin/SecurityPolicy.h"
 
 namespace blink {
 
 inline RemoteFrame::RemoteFrame(RemoteFrameClient* client, FrameHost* host, FrameOwner* owner)
     : Frame(client, host, owner)
 {
 }
 
 PassRefPtrWillBeRawPtr<RemoteFrame> RemoteFrame::create(RemoteFrameClient* client, FrameHost* host, FrameOwner* owner)
 {
     return adoptRefWillBeNoop(new RemoteFrame(client, host, owner));
 }
 
 RemoteFrame::~RemoteFrame()
 {
     setView(nullptr);
 }
 
+void RemoteFrame::trace(Visitor* visitor)
+{
+    visitor->trace(m_view);
+    Frame::trace(visitor);
+}
+
 void RemoteFrame::navigate(Document& originDocument, const KURL& url, bool lockBackForwardList)
 {
     // The process where this frame actually lives won't have sufficient information to determine
     // correct referrer, since it won't have access to the originDocument. Set it now.
     ResourceRequest request(url);
     request.setHTTPReferrer(SecurityPolicy::generateReferrer(originDocument.referrerPolicy(), url, originDocument.outgoingReferrer()));
     remoteFrameClient()->navigate(request, lockBackForwardList);
 }
 
 void RemoteFrame::detach()
 {
     detachChildren();
     if (!client())
         return;
     Frame::detach();
 }
 
 void RemoteFrame::forwardInputEvent(Event* event)
 {
     remoteFrameClient()->forwardInputEvent(event);
 }
 
-void RemoteFrame::trace(Visitor* visitor)
-{
-    visitor->trace(m_view);
-    Frame::trace(visitor);
-}
-
 void RemoteFrame::setView(PassRefPtrWillBeRawPtr<RemoteFrameView> view)
 {
     // Oilpan: as RemoteFrameView performs no finalization actions,
     // no explicit dispose() of it needed here. (cf. FrameView::dispose().)
     m_view = view;
 }
 
 void RemoteFrame::createView()
 {
     RefPtrWillBeRawPtr<RemoteFrameView> view = RemoteFrameView::create(this);
     setView(view);
 
     if (ownerRenderer()) {
         HTMLFrameOwnerElement* owner = deprecatedLocalOwner();
         ASSERT(owner);
         owner->setWidget(view);
     }
 }
 
 RemoteFrameClient* RemoteFrame::remoteFrameClient() const
 {
     return static_cast<RemoteFrameClient*>(client());
 }
 
 } // namespace blink