Avoid parsing css text if there are identical inline style blocks.

Source/core/css/CSSStyleSheet.h

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2006, 2007, 2008, 2009, 2010, 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 28 matching lines @@
 class ExceptionState;
 class MediaQuerySet;
 class SecurityOrigin;
 class StyleSheetContents;
 
 class CSSStyleSheet : public StyleSheet {
 public:
     static PassRefPtr<CSSStyleSheet> create(PassRefPtr<StyleSheetContents>, CSSImportRule* ownerRule = 0);
     static PassRefPtr<CSSStyleSheet> create(PassRefPtr<StyleSheetContents>, Node* ownerNode);
     static PassRefPtr<CSSStyleSheet> createInline(Node*, const KURL&, const TextPosition& startPosition = TextPosition::minimumPosition(), const String& encoding = String());
+    static PassRefPtr<CSSStyleSheet> createInline(PassRefPtr<StyleSheetContents>, Node* ownerNode, const TextPosition& startPosition = TextPosition::minimumPosition());
 
     virtual ~CSSStyleSheet();
 
     virtual CSSStyleSheet* parentStyleSheet() const OVERRIDE;
     virtual Node* ownerNode() const OVERRIDE { return m_ownerNode; }
     virtual MediaList* media() const OVERRIDE;
     virtual String href() const OVERRIDE;
     virtual String title() const OVERRIDE { return m_title; }
     virtual bool disabled() const OVERRIDE { return m_isDisabled; }
     virtual void setDisabled(bool) OVERRIDE;
@@ skipping 87 matching lines @@
 
 inline CSSStyleSheet::RuleMutationScope::~RuleMutationScope()
 {
     if (m_styleSheet)
         m_styleSheet->didMutateRules();
 }
 
 } // namespace
 
 #endif