Refactor frame detach to work for both local and remote frames.

Source/core/page/Page.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012, 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,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 584 matching lines @@
     visitor->trace(m_multisamplingChangedObservers);
     visitor->trace(m_frameHost);
 #endif
     WillBeHeapSupplementable<Page>::trace(visitor);
 }
 
 void Page::willBeDestroyed()
 {
     RefPtr<Frame> mainFrame = m_mainFrame;
 
-    if (mainFrame->isLocalFrame())
-        toLocalFrame(mainFrame.get())->loader().frameDetached();
+    mainFrame->detach();
 
     // Disable all agents prior to resetting the frame view.
     m_inspectorController->willBeDestroyed();
 
     if (mainFrame->isLocalFrame()) {
         toLocalFrame(mainFrame.get())->setView(nullptr);
     } else {
         ASSERT(m_mainFrame->isRemoteFrame());
         toRemoteFrame(mainFrame.get())->setView(nullptr);
     }
@@ skipping 26 matching lines @@
     , spellCheckerClient(0)
     , storageClient(0)
 {
 }
 
 Page::PageClients::~PageClients()
 {
 }
 
 } // namespace blink