Refactor StyleInvalidator to encapsulate all style invalidation state.

Source/core/dom/Element.cpp

Index: Source/core/dom/Element.cpp
diff --git a/Source/core/dom/Element.cpp b/Source/core/dom/Element.cpp
index b9b4bc34d3252610156931ced3eb358522b22e76..46a60530d0b130782ebda7e27959f8d543530c1a 100644
--- a/Source/core/dom/Element.cpp
+++ b/Source/core/dom/Element.cpp
@@ -1084,11 +1084,11 @@ void Element::classAttributeChanged(const AtomicString& newClassString)
         elementData()->setClass(newClassString, shouldFoldCase);
         const SpaceSplitString& newClasses = elementData()->classNames();
         if (testShouldInvalidateStyle)
-            styleResolver->ensureUpdatedRuleFeatureSet().scheduleStyleInvalidationForClassChange(oldClasses, newClasses, this);
+            styleResolver->ensureUpdatedRuleFeatureSet().scheduleStyleInvalidationForClassChange(oldClasses, newClasses, *this);
     } else {
         const SpaceSplitString& oldClasses = elementData()->classNames();
         if (testShouldInvalidateStyle)
-            styleResolver->ensureUpdatedRuleFeatureSet().scheduleStyleInvalidationForClassChange(oldClasses, this);
+            styleResolver->ensureUpdatedRuleFeatureSet().scheduleStyleInvalidationForClassChange(oldClasses, *this);
         elementData()->clearClass();
     }
 
@@ -2875,7 +2875,7 @@ void Element::willModifyAttribute(const QualifiedName& name, const AtomicString&
 
     if (oldValue != newValue) {
         if (inActiveDocument())
-            document().ensureStyleResolver().ensureUpdatedRuleFeatureSet().scheduleStyleInvalidationForAttributeChange(name, this);
+            document().ensureStyleResolver().ensureUpdatedRuleFeatureSet().scheduleStyleInvalidationForAttributeChange(name, *this);
 
         if (isUpgradedCustomElement())
             CustomElement::attributeDidChange(this, name.localName(), oldValue, newValue);