Remove LifecycleNotifier<>::m_context.

Source/core/dom/Document.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
@@ skipping 386 matching lines @@
 
 void DocumentVisibilityObserver::setObservedDocument(Document& document)
 {
     unregisterObserver();
     registerObserver(document);
 }
 
 Document::Document(const DocumentInit& initializer, DocumentClassFlags documentClasses)
     : ContainerNode(0, CreateDocument)
     , TreeScope(*this)
-    , DocumentLifecycleNotifier(this)
     , m_hasNodesWithPlaceholderStyle(false)
     , m_evaluateMediaQueriesOnStyleRecalc(false)
     , m_pendingSheetLayout(NoLayoutWithPendingSheets)
     , m_frame(initializer.frame())
     , m_domWindow(m_frame ? m_frame->localDOMWindow() : 0)
     , m_importsController(initializer.importsController())
     , m_activeParserCount(0)
     , m_contextFeatures(ContextFeatures::defaultSwitch())
     , m_wellFormed(false)
     , m_printing(false)
@@ skipping 5317 matching lines @@
 #ifndef NDEBUG
 using namespace blink;
 void showLiveDocumentInstances()
 {
     WeakDocumentSet& set = liveDocumentSet();
     fprintf(stderr, "There are %u documents currently alive:\n", set.size());
     for (Document* document : set)
         fprintf(stderr, "- Document %p URL: %s\n", document, document->url().string().utf8().data());
 }
 #endif