Simplify window.closed testing.

Source/core/frame/Frame.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 45 matching lines @@
 using namespace HTMLNames;
 
 DEFINE_DEBUG_ONLY_GLOBAL(WTF::RefCountedLeakCounter, frameCounter, ("Frame"));
 
 Frame::Frame(FrameClient* client, FrameHost* host, FrameOwner* owner)
     : m_treeNode(this)
     , m_host(host)
     , m_owner(owner)
     , m_client(client)
     , m_remotePlatformLayer(0)
-    , m_hasBeenClosed(false)
 {
     ASSERT(page());
 
 #ifndef NDEBUG
     frameCounter.increment();
 #endif
 
     if (m_owner) {
         page()->incrementSubframeCount();
         if (m_owner->isLocal())
@@ skipping 39 matching lines @@
     return 0;
 }
 
 Settings* Frame::settings() const
 {
     if (m_host)
         return &m_host->settings();
     return 0;
 }
 
-void Frame::setHasBeenClosed()
-{
-    ASSERT(!m_hasBeenClosed);
-    m_hasBeenClosed = true;
-}
-
 void Frame::setDOMWindow(PassRefPtrWillBeRawPtr<LocalDOMWindow> domWindow)
 {
     if (m_domWindow)
         m_domWindow->reset();
     m_domWindow = domWindow;
 }
 
 static ChromeClient& emptyChromeClient()
 {
     DEFINE_STATIC_LOCAL(EmptyChromeClient, client, ());
@@ skipping 64 matching lines @@
     }
     m_owner = 0;
 }
 
 HTMLFrameOwnerElement* Frame::deprecatedLocalOwner() const
 {
     return m_owner && m_owner->isLocal() ? toHTMLFrameOwnerElement(m_owner) : 0;
 }
 
 } // namespace blink