Move the Widget hierarchy to the Oilpan heap.

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"
@@ skipping 25 matching lines @@
     request.setHTTPReferrer(referrer);
     remoteFrameClient()->navigate(request, lockBackForwardList);
 }
 
 void RemoteFrame::detach()
 {
     detachChildren();
     m_host = nullptr;
 }
 
-void RemoteFrame::setView(PassRefPtr<RemoteFrameView> view)
+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()
 {
-    RefPtr<RemoteFrameView> view = RemoteFrameView::create(this);
+    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