Simplify StyleEngine clean up.

sky/engine/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 313 matching lines @@
     detachParser();
 #endif
 
 #if !ENABLE(OILPAN)
 
     if (m_importsController)
         HTMLImportsController::removeFrom(*this);
 
     m_timeline->detachFromDocument();
 
-    // We need to destroy CSSFontSelector before destroying m_fetcher.
-    if (m_styleEngine)
-        m_styleEngine->detachFromDocument();
-
     if (m_elemSheet)
         m_elemSheet->clearOwnerNode();
 
     m_fetcher.clear();
 
     // We must call clearRareData() here since a Document class inherits TreeScope
     // as well as Node. See a comment on TreeScope.h for the reason.
     if (hasRareData())
         clearRareData();
 
@@ skipping 928 matching lines @@
     if (m_domWindow)
         m_domWindow->clearEventQueue();
 
     m_hoverNode = nullptr;
     m_focusedElement = nullptr;
     m_activeHoverElement = nullptr;
 
     m_renderView = 0;
     ContainerNode::detach(context);
 
-    m_styleEngine->didDetach();
     m_styleEngine = nullptr;
 
     // This is required, as our LocalFrame might delete itself as soon as it detaches
     // us. However, this violates Node::detach() semantics, as it's never
     // possible to re-attach. Eventually Document::detach() should be renamed,
     // or this setting of the frame to 0 could be made explicit in each of the
     // callers of Document::detach().
     m_frame = 0;
 
     if (m_mediaQueryMatcher)
@@ skipping 1466 matching lines @@
 using namespace blink;
 void showLiveDocumentInstances()
 {
     WeakDocumentSet& set = liveDocumentSet();
     fprintf(stderr, "There are %u documents currently alive:\n", set.size());
     for (WeakDocumentSet::const_iterator it = set.begin(); it != set.end(); ++it) {
         fprintf(stderr, "- Document %p URL: %s\n", *it, (*it)->url().string().utf8().data());
     }
 }
 #endif