Reland "Streamline frame detach"

Source/core/frame/RemoteFrame.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/frame/RemoteFrame.h"
 
 #include "core/frame/RemoteFrameClient.h"
 #include "core/frame/RemoteFrameView.h"
 #include "core/html/HTMLFrameOwnerElement.h"
@@ skipping 22 matching lines @@
     // correct referrer, since it won't have access to the originDocument. Set it now.
     ResourceRequest request(url);
     Referrer referrer(SecurityPolicy::generateReferrerHeader(originDocument.referrerPolicy(), url, originDocument.outgoingReferrer()), originDocument.referrerPolicy());
     request.setHTTPReferrer(referrer);
     remoteFrameClient()->navigate(request, lockBackForwardList);
 }
 
 void RemoteFrame::detach()
 {
     detachChildren();
-    m_host = nullptr;
+    Frame::detach();
 }
 
 void RemoteFrame::trace(Visitor* visitor)
 {
     visitor->trace(m_view);
     Frame::trace(visitor);
 }
 
 void RemoteFrame::setView(PassRefPtrWillBeRawPtr<RemoteFrameView> view)
 {
@@ skipping 13 matching lines @@
         owner->setWidget(view);
     }
 }
 
 RemoteFrameClient* RemoteFrame::remoteFrameClient() const
 {
     return static_cast<RemoteFrameClient*>(client());
 }
 
 } // namespace blink