RemoteBridgeFrameOwner: keep better track of the attached frame

third_party/WebKit/Source/core/html/HTMLFrameOwnerElement.cpp

 /*
  * Copyright (C) 2006, 2007, 2009 Apple Inc. All rights reserved.
  *
  * 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 147 matching lines @@
 
     for (ContainerNode* node = this; node; node = node->parentOrShadowHostNode())
         node->incrementConnectedSubframeCount();
 }
 
 void HTMLFrameOwnerElement::clearContentFrame()
 {
     if (!m_contentFrame)
         return;
 
+    ASSERT(m_contentFrame->owner() == this);
     m_contentFrame = nullptr;
 
     for (ContainerNode* node = this; node; node = node->parentOrShadowHostNode())
         node->decrementConnectedSubframeCount();
 }
 
 void HTMLFrameOwnerElement::disconnectContentFrame()
 {
     // FIXME: Currently we don't do this in removedFrom because this causes an
     // unload event in the subframe which could execute script that could then
@@ skipping 128 matching lines @@
 DEFINE_TRACE(HTMLFrameOwnerElement)
 {
     visitor->trace(m_contentFrame);
     visitor->trace(m_widget);
     HTMLElement::trace(visitor);
     FrameOwner::trace(visitor);
 }
 
 
 } // namespace blink