Add fast-path for propagated variable changes (WIP)

third_party/WebKit/Source/core/style/ComputedStyle.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 210 matching lines @@
              (m_textTransform == other.m_textTransform) &&
              (m_textUnderline == other.m_textUnderline) &&
              (m_cursorStyle == other.m_cursorStyle) &&
              (m_direction == other.m_direction) &&
              (m_whiteSpace == other.m_whiteSpace) &&
              (m_borderCollapse == other.m_borderCollapse) &&
              (m_boxDirection == other.m_boxDirection) &&
              (m_rtlOrdering == other.m_rtlOrdering) &&
              (m_printColorAdjust == other.m_printColorAdjust) &&
              (m_insideLink == other.m_insideLink) &&
-             (m_writingMode == other.m_writingMode);
+             (m_writingMode == other.m_writingMode) &&
+             (m_variableReference == other.m_variableReference);
     }
 
     unsigned m_captionSide : 2;        // ECaptionSide
     unsigned m_listStyleType : 7;      // EListStyleType
     unsigned m_listStylePosition : 1;  // EListStylePosition
     unsigned m_textAlign : 4;          // ETextAlign
     unsigned m_textTransform : 2;      // ETextTransform
     unsigned m_textUnderline : 1;
     unsigned m_cursorStyle : 6;     // ECursor
     unsigned m_direction : 1;       // TextDirection
     unsigned m_whiteSpace : 3;      // EWhiteSpace
     unsigned m_borderCollapse : 1;  // EBorderCollapse
     unsigned m_boxDirection : 1;  // EBoxDirection (CSS3 box_direction property,
                                   // flexible box layout module)
     // 32 bits
 
     // non CSS2 inherited
     unsigned m_rtlOrdering : 1;  // Order
     unsigned m_printColorAdjust : PrintColorAdjustBits;
     unsigned m_pointerEvents : 4;  // EPointerEvents
     unsigned m_insideLink : 2;     // EInsideLink
 
     // CSS Text Layout Module Level 3: Vertical writing support
     unsigned m_writingMode : 2;  // WritingMode
-                                 // 42 bits
+
+    unsigned m_variableReference : 1;  // Whether an inherited property
+                                       // references a variable.
+                                       // 43 bits
   } m_inheritedData;
 
   // don't inherit
   struct NonInheritedData {
     // Compare computed styles, differences in inherited bits or other flags
     // should not cause an inequality.
     bool operator==(const NonInheritedData& other) const {
       return m_effectiveDisplay == other.m_effectiveDisplay &&
              m_originalDisplay == other.m_originalDisplay &&
              m_overflowAnchor == other.m_overflowAnchor &&
@@ skipping 105 matching lines @@
     m_inheritedData.m_cursorStyle = initialCursor();
     m_inheritedData.m_direction = initialDirection();
     m_inheritedData.m_whiteSpace = initialWhiteSpace();
     m_inheritedData.m_borderCollapse = initialBorderCollapse();
     m_inheritedData.m_rtlOrdering = initialRTLOrdering();
     m_inheritedData.m_boxDirection = initialBoxDirection();
     m_inheritedData.m_printColorAdjust = initialPrintColorAdjust();
     m_inheritedData.m_pointerEvents = initialPointerEvents();
     m_inheritedData.m_insideLink = NotInsideLink;
     m_inheritedData.m_writingMode = initialWritingMode();
+    m_inheritedData.m_variableReference = false;
 
     m_nonInheritedData.m_effectiveDisplay =
         m_nonInheritedData.m_originalDisplay =
             static_cast<unsigned>(initialDisplay());
     m_nonInheritedData.m_overflowAnchor = initialOverflowAnchor();
     m_nonInheritedData.m_overflowX = initialOverflowX();
     m_nonInheritedData.m_overflowY = initialOverflowY();
     m_nonInheritedData.m_verticalAlign = initialVerticalAlign();
     m_nonInheritedData.m_clear = initialClear();
     m_nonInheritedData.m_position = initialPosition();
@@ skipping 2251 matching lines @@
   }
 
   // Comparison operators
   bool operator==(const ComputedStyle& other) const;
   bool operator!=(const ComputedStyle& other) const {
     return !(*this == other);
   }
 
   bool inheritedEqual(const ComputedStyle&) const;
   bool nonInheritedEqual(const ComputedStyle&) const;
+
+  // Compares independent inherited properties, not including variables.
   inline bool independentInheritedEqual(const ComputedStyle&) const;
   inline bool nonIndependentInheritedEqual(const ComputedStyle&) const;
+
+  // Compares variables.
+  inline bool variablesEqual(const ComputedStyle&) const;
+
   bool loadingCustomFontsEqual(const ComputedStyle&) const;
   bool inheritedDataShared(const ComputedStyle&) const;
 
   bool hasChildDependentFlags() const {
     return emptyState() || hasExplicitlyInheritedProperties();
   }
   void copyChildDependentFlagsFrom(const ComputedStyle&);
 
   // Counters.
   const CounterDirectiveMap* counterDirectives() const;
@@ skipping 33 matching lines @@
 
   // Handles both inherited and non-inherited variables
   CSSVariableData* getVariable(const AtomicString&) const;
 
   void setHasVariableReferenceFromNonInheritedProperty() {
     m_nonInheritedData.m_variableReference = true;
   }
   bool hasVariableReferenceFromNonInheritedProperty() const {
     return m_nonInheritedData.m_variableReference;
   }
+  void setHasVariableReferenceFromInheritedProperty() {
+    m_inheritedData.m_variableReference = true;
+  }
+  bool hasVariableReferenceFromInheritedProperty() const {
+    return m_inheritedData.m_variableReference;
+  }
 
   // Animations.
   CSSAnimationData& accessAnimations();
   const CSSAnimationData* animations() const {
     return m_rareNonInheritedData->m_animations.get();
   }
 
   // Transitions.
   const CSSTransitionData* transitions() const {
     return m_rareNonInheritedData->m_transitions.get();
@@ skipping 1385 matching lines @@
   m_nonInheritedData.m_pseudoBits |= 1 << (pseudo - 1);
 }
 
 inline bool ComputedStyle::hasPseudoElementStyle() const {
   return m_nonInheritedData.m_pseudoBits & ElementPseudoIdMask;
 }
 
 }  // namespace blink
 
 #endif  // ComputedStyle_h