Introduce SynchronousMutationObserver::didChangeAttribute()

third_party/WebKit/Source/core/dom/SynchronousMutationObserver.h

Index: third_party/WebKit/Source/core/dom/SynchronousMutationObserver.h
diff --git a/third_party/WebKit/Source/core/dom/SynchronousMutationObserver.h b/third_party/WebKit/Source/core/dom/SynchronousMutationObserver.h
index ad0311ca64c0168fee3532f37ab0ec9647d59f5a..8d4d17fbafd75f0e96d231b848bfbaee65ce5c0b 100644
--- a/third_party/WebKit/Source/core/dom/SynchronousMutationObserver.h
+++ b/third_party/WebKit/Source/core/dom/SynchronousMutationObserver.h
@@ -14,6 +14,7 @@ namespace blink {
 class CharacterData;
 class ContainerNode;
 class Document;
+class Element;
 class NodeWithIndex;
 class Text;
 
@@ -40,6 +41,9 @@ class CORE_EXPORT SynchronousMutationObserver
   //  - didInsertText(Node*, unsigned offset, unsigned length);
   //  - didRemoveText(Node*, unsigned offset, unsigned length);
 
+  // Called just after attribute is changed.
+  virtual void didChangeAttribute(const Element&);
+
   // Called after child nodes changed.
   virtual void didChangeChildren(const ContainerNode&);