Use ChildFrameDisconnector when detaching child frames of a LocalFrame.

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>
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
@@ skipping 13 matching lines @@
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #include "core/frame/LocalFrame.h"
 
 #include "bindings/core/v8/ScriptController.h"
 #include "core/InstrumentingAgents.h"
+#include "core/dom/ChildFrameDisconnector.h"
 #include "core/dom/DocumentType.h"
 #include "core/dom/StyleChangeReason.h"
 #include "core/editing/EditingUtilities.h"
 #include "core/editing/Editor.h"
 #include "core/editing/FrameSelection.h"
 #include "core/editing/InputMethodController.h"
 #include "core/editing/serializers/Serialization.h"
 #include "core/editing/spellcheck/SpellChecker.h"
 #include "core/events/Event.h"
 #include "core/fetch/ResourceFetcher.h"
@@ skipping 396 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());
+
+    if (document())

[esprehn, 2016/07/13 02:35:45]

if (Document* document = this->document())

avoids the nested virtual calls down there.

[dcheng, 2016/07/13 02:51:34]

Done.

+        ChildFrameDisconnector(*document()).disconnect();
+}
+
 void LocalFrame::willDetachFrameHost()
 {
     LocalFrameLifecycleNotifier::notifyWillDetachFrameHost();
 
     // FIXME: Page should take care of updating focus/scrolling instead of Frame.
     // FIXME: It's unclear as to why this is called more than once, but it is,
     // so page() could be null.
     if (page() && page()->focusController().focusedFrame() == this)
         page()->focusController().setFocusedFrame(nullptr);
 
@@ skipping 406 matching lines @@
         m_frame->client()->frameBlameContext()->Enter();
 }
 
 ScopedFrameBlamer::~ScopedFrameBlamer()
 {
     if (m_frame && m_frame->client() && m_frame->client()->frameBlameContext())
         m_frame->client()->frameBlameContext()->Leave();
 }
 
 } // namespace blink