Call LocalDOMWindow::clearDocument when a frame gets detached

third_party/WebKit/Source/core/frame/LocalFrame.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Simon Hausmann <hausmann@kde.org>
  *                     2000 Stefan Schimanski <1Stein@gmx.de>
  *                     2001 George Staikos <staikos@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2005 Alexey Proskuryakov <ap@nypop.com>
@@ skipping 380 matching lines @@
   // DCHECK(!m_isDetaching) here.
   m_isDetaching = true;
 
   PluginScriptForbiddenScope forbidPluginDestructorScripting;
   m_loader.stopAllLoaders();
   // Don't allow any new child frames to load in this frame: attaching a new
   // child frame during or after detaching children results in an attached
   // frame on a detached DOM tree, which is bad.
   SubframeLoadingDisabler disabler(*document());
   m_loader.dispatchUnloadEvent();
+  if (!client())
+    return;
   detachChildren();
 
   // All done if detaching the subframes brought about a detach of this frame
   // also.
   if (!client())
     return;
 
   // stopAllLoaders() needs to be called after detachChildren(), because
   // detachChildren() will trigger the unload event handlers of any child
   // frames, and those event handlers might start a new subresource load in this
@@ skipping 67 matching lines @@
   return m_script->getWindowProxyManager();
 }
 
 bool LocalFrame::shouldClose() {
   // TODO(dcheng): This should be fixed to dispatch beforeunload events to
   // both local and remote frames.
   return m_loader.shouldClose();
 }
 
 void LocalFrame::detachChildren() {
-  DCHECK(m_loader.stateMachine()->creatingInitialEmptyDocument() || document());
+  CHECK(m_loader.stateMachine()->creatingInitialEmptyDocument() || document());
 
   if (Document* document = this->document())
     ChildFrameDisconnector(*document).disconnect();
 }
 
 void LocalFrame::documentAttached() {
   DCHECK(document());
   selection().documentAttached(document());
   inputMethodController().documentAttached(document());
 }
@@ skipping 427 matching lines @@
   if (m_frame && m_frame->client() && m_frame->client()->frameBlameContext())
     m_frame->client()->frameBlameContext()->Enter();
 }
 
 ScopedFrameBlamer::~ScopedFrameBlamer() {
   if (m_frame && m_frame->client() && m_frame->client()->frameBlameContext())
     m_frame->client()->frameBlameContext()->Leave();
 }
 
 }  // namespace blink