Improve window.closed fidelity.

Source/core/frame/LocalDOMWindow.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 799 matching lines @@
         frameConsole()->addMessage(ConsoleMessage::create(JSMessageSource, WarningMessageLevel, "Scripts may close only the windows that were opened by it."));
         return;
     }
 
     if (!frame()->loader().shouldClose())
         return;
 
     InspectorInstrumentation::willCloseWindow(context);
 
     page->chrome().closeWindowSoon();
+    // So as to make window.closed return the expected result
+    // after window.close(), separately record the to-be-closed
+    // state of this window. Scripts may access window.closed
+    // before the deferred close operation has gone ahead.
+    m_windowIsClosing = true;
 }
 
 void LocalDOMWindow::print()
 {
     if (!frame())
         return;
 
     FrameHost* host = frame()->host();
     if (!host)
         return;
@@ skipping 829 matching lines @@
     return m_frameObserver->frame();
 }
 
 v8::Handle<v8::Object> LocalDOMWindow::wrap(v8::Handle<v8::Object> creationContext, v8::Isolate* isolate)
 {
     ASSERT_NOT_REACHED(); // LocalDOMWindow has [Custom=ToV8].
     return v8::Handle<v8::Object>();
 }
 
 } // namespace blink