Lazy Parse CSS

third_party/WebKit/Source/core/css/StyleRule.h

Index: third_party/WebKit/Source/core/css/StyleRule.h
diff --git a/third_party/WebKit/Source/core/css/StyleRule.h b/third_party/WebKit/Source/core/css/StyleRule.h
index f7098ecadac418056cfe9af359b134ddbb27045a..1394c876241ee6317a9965ed34a06b8b40f1b78c 100644
--- a/third_party/WebKit/Source/core/css/StyleRule.h
+++ b/third_party/WebKit/Source/core/css/StyleRule.h
@@ -97,11 +97,15 @@ public:
     {
         return new StyleRule(std::move(selectorList), properties);
     }
+    static StyleRule* createLazy(CSSSelectorList selectorList, std::unique_ptr<DeferredPropertiesClosure> deferredProperties)
+    {
+        return new StyleRule(std::move(selectorList), std::move(deferredProperties));
+    }
 
     ~StyleRule();
 
     const CSSSelectorList& selectorList() const { return m_selectorList; }
-    const StylePropertySet& properties() const { return *m_properties; }
+    const StylePropertySet& properties() const;
     MutableStylePropertySet& mutableProperties();
 
     void wrapperAdoptSelectorList(CSSSelectorList selectors) { m_selectorList = std::move(selectors); }
@@ -110,14 +114,20 @@ public:
 
     static unsigned averageSizeInBytes();
 
+    // Helper methods to avoid parsing lazy properties when not needed.
+    bool propertiesHaveFailedOrCanceledSubresources() const;
+    bool shouldConsiderForMatchingRules(bool includeEmptyRules) const;
+
     DECLARE_TRACE_AFTER_DISPATCH();
 
 private:
     StyleRule(CSSSelectorList, StylePropertySet*);
+    StyleRule(CSSSelectorList, std::unique_ptr<DeferredPropertiesClosure>);
     StyleRule(const StyleRule&);
 
-    Member<StylePropertySet> m_properties; // Cannot be null.
     CSSSelectorList m_selectorList;
+    mutable Member<StylePropertySet> m_properties;
+    mutable std::unique_ptr<DeferredPropertiesClosure> m_deferred;
 };
 
 class StyleRuleFontFace : public StyleRuleBase {