Add fast-path for propagated variable changes (WIP)

third_party/WebKit/Source/core/style/StyleRareInheritedData.cpp

 /*
  * Copyright (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 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.
  *
@@ skipping 156 matching lines @@
       textEmphasisCustomMark(o.textEmphasisCustomMark),
       tapHighlightColor(o.tapHighlightColor),
       appliedTextDecorations(o.appliedTextDecorations),
       m_tabSize(o.m_tabSize),
       variables(o.variables),
       m_textSizeAdjust(o.m_textSizeAdjust) {}
 
 StyleRareInheritedData::~StyleRareInheritedData() {}
 
 bool StyleRareInheritedData::operator==(const StyleRareInheritedData& o) const {
+  return compareEqualVariables(o) && compareEqualNonVariables(o);
+}
+
+bool StyleRareInheritedData::compareEqualNonVariables(
+    const StyleRareInheritedData& o) const {
   return m_textStrokeColor == o.m_textStrokeColor &&
          textStrokeWidth == o.textStrokeWidth &&
          m_textFillColor == o.m_textFillColor &&
          m_textEmphasisColor == o.m_textEmphasisColor &&
          m_visitedLinkTextStrokeColor == o.m_visitedLinkTextStrokeColor &&
          m_visitedLinkTextFillColor == o.m_visitedLinkTextFillColor &&
          m_visitedLinkTextEmphasisColor == o.m_visitedLinkTextEmphasisColor &&
          tapHighlightColor == o.tapHighlightColor && shadowDataEquivalent(o) &&
          highlight == o.highlight &&
          dataEquivalent(cursorData.get(), o.cursorData.get()) &&
@@ skipping 33 matching lines @@
          hyphenationString == o.hyphenationString &&
          m_snapHeightUnit == o.m_snapHeightUnit &&
          textEmphasisCustomMark == o.textEmphasisCustomMark &&
          quotesDataEquivalent(o) && m_tabSize == o.m_tabSize &&
          m_imageRendering == o.m_imageRendering &&
          m_textUnderlinePosition == o.m_textUnderlinePosition &&
          m_textDecorationSkip == o.m_textDecorationSkip &&
          m_rubyPosition == o.m_rubyPosition &&
          dataEquivalent(listStyleImage.get(), o.listStyleImage.get()) &&
          dataEquivalent(appliedTextDecorations, o.appliedTextDecorations) &&
-         dataEquivalent(variables, o.variables) &&
          m_textSizeAdjust == o.m_textSizeAdjust;
 }
 
+bool StyleRareInheritedData::compareEqualVariables(
+    const StyleRareInheritedData& o) const {
+  return dataEquivalent(variables, o.variables);
+}
+
 bool StyleRareInheritedData::shadowDataEquivalent(
     const StyleRareInheritedData& o) const {
   return dataEquivalent(textShadow.get(), o.textShadow.get());
 }
 
 bool StyleRareInheritedData::quotesDataEquivalent(
     const StyleRareInheritedData& o) const {
   return dataEquivalent(quotes, o.quotes);
 }
 
 }  // namespace blink