Have window.closed return true when frame is closed.

Source/web/WebRemoteFrameImpl.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 "web/WebRemoteFrameImpl.h"
 
 #include "core/frame/FrameOwner.h"
 #include "core/frame/RemoteFrame.h"
 #include "core/frame/Settings.h"
@@ skipping 112 matching lines @@
     return true;
 }
 
 WebRemoteFrame* WebRemoteFrameImpl::toWebRemoteFrame()
 {
     return this;
 }
 
 void WebRemoteFrameImpl::close()
 {
+    if (m_frame)
+        m_frame->setHasBeenClosed();
+
     deref();
 }
 
 WebString WebRemoteFrameImpl::uniqueName() const
 {
     ASSERT_NOT_REACHED();
     return WebString();
 }
 
 WebString WebRemoteFrameImpl::assignedName() const
@@ skipping 685 matching lines @@
 }
 
 WebRemoteFrameImpl* WebRemoteFrameImpl::fromFrame(RemoteFrame& frame)
 {
     if (!frame.client())
         return 0;
     return static_cast<RemoteFrameClient*>(frame.client())->webFrame();
 }
 
 } // namespace blink
-