Delay calling FrameOwner::setWidget when doing a remote->local frame transition

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>
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
@@ skipping 465 matching lines @@
 
     frameView->updateBackgroundRecursively(backgroundColor, transparent);
 
     if (isLocalRoot)
         frameView->setParentVisible(true);
 
     // FIXME: Not clear what the right thing for OOPI is here.
     if (ownerRenderer()) {
         HTMLFrameOwnerElement* owner = deprecatedLocalOwner();
         ASSERT(owner);
-        owner->setWidget(frameView);
+        // FIXME: OOPI might lead to us temporarily lying to a frame and telling it
+        // that it's owned by a FrameOwner that knows nothing about it. If we're
+        // lying to this frame, don't let it clobber the existing widget.
+        if (owner->contentFrame() == this)
+            owner->setWidget(frameView);
     }
 
     if (HTMLFrameOwnerElement* owner = deprecatedLocalOwner())
         view()->setCanHaveScrollbars(owner->scrollingMode() != ScrollbarAlwaysOff);
 }
 
 
 void LocalFrame::countObjectsNeedingLayout(unsigned& needsLayoutObjects, unsigned& totalObjects, bool& isPartial)
 {
     RenderObject* root = view()->layoutRoot();
@@ skipping 276 matching lines @@
 }
 
 void LocalFrame::unregisterPluginElement(HTMLPlugInElement* plugin)
 {
     ASSERT(m_pluginElements.contains(plugin));
     m_pluginElements.remove(plugin);
 }
 #endif
 
 } // namespace blink