Special-case LocalDOMWindow for same-origin access in bindings.

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 514 matching lines @@
 void LocalFrame::setDOMWindow(LocalDOMWindow* domWindow) {
   if (domWindow)
     script().clearWindowProxy();
 
   if (this->domWindow())
     this->domWindow()->reset();
   m_domWindow = domWindow;
 }
 
 Document* LocalFrame::document() const {
-  return m_domWindow ? m_domWindow->document() : nullptr;
+  return domWindow() ? domWindow()->document() : nullptr;
 }
 
 void LocalFrame::setPagePopupOwner(Element& owner) {
   m_pagePopupOwner = &owner;
 }
 
 LayoutView* LocalFrame::contentLayoutObject() const {
   return document() ? document()->layoutView() : nullptr;
 }
 
@@ skipping 393 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