Remove the concept of user stylesheets.

Source/core/css/StyleSheetContents.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2006, 2007, 2012 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 39 matching lines @@
         if (StyleSheetContents* sheet = m_importRules[i]->styleSheet())
             size += sheet->estimatedSizeInBytes();
     }
     return size;
 }
 
 StyleSheetContents::StyleSheetContents(StyleRuleImport* ownerRule, const String& originalURL, const CSSParserContext& context)
     : m_ownerRule(ownerRule)
     , m_originalURL(originalURL)
     , m_loadCompleted(false)
-    , m_isUserStyleSheet(ownerRule && ownerRule->parentStyleSheet() && ownerRule->parentStyleSheet()->isUserStyleSheet())
     , m_hasSyntacticallyValidCSSHeader(true)
     , m_didLoadErrorOccur(false)
     , m_usesRemUnits(false)
     , m_isMutable(false)
     , m_isInMemoryCache(false)
     , m_parserContext(context)
 {
 }
 
 StyleSheetContents::StyleSheetContents(const StyleSheetContents& o)
     : RefCounted<StyleSheetContents>()
     , m_ownerRule(0)
     , m_originalURL(o.m_originalURL)
     , m_encodingFromCharsetRule(o.m_encodingFromCharsetRule)
     , m_importRules(o.m_importRules.size())
     , m_childRules(o.m_childRules.size())
     , m_namespaces(o.m_namespaces)
     , m_loadCompleted(true)
-    , m_isUserStyleSheet(o.m_isUserStyleSheet)
     , m_hasSyntacticallyValidCSSHeader(o.m_hasSyntacticallyValidCSSHeader)
     , m_didLoadErrorOccur(false)
     , m_usesRemUnits(o.m_usesRemUnits)
     , m_isMutable(false)
     , m_isInMemoryCache(false)
     , m_parserContext(o.m_parserContext)
 {
     ASSERT(o.isCacheable());
 
     // FIXME: Copy import rules.
@@ skipping 405 matching lines @@
     m_isInMemoryCache = false;
 }
 
 void StyleSheetContents::shrinkToFit()
 {
     m_importRules.shrinkToFit();
     m_childRules.shrinkToFit();
 }
 
 }