Bug 1290214 - Make ServoRestyleManager::AttributeChanged a no-op. r=emilio

We do all the work we need to do with the snapshot model in AttributeWillChange.

layout/base/ServoRestyleManager.cpp

@@ -296,14 +296,6 @@ ServoRestyleManager::AttributeWillChange(Element* aElement,
   snapshot->AddAttrs(aElement);
 }
 
-void
-ServoRestyleManager::AttributeChanged(Element* aElement, int32_t aNameSpaceID,
-                                      nsIAtom* aAttribute, int32_t aModType,
-                                      const nsAttrValue* aOldValue)
-{
-  NS_ERROR("stylo: ServoRestyleManager::AttributeChanged not implemented");
-}
-
 nsresult
 ServoRestyleManager::ReparentStyleContext(nsIFrame* aFrame)
 {

layout/base/ServoRestyleManager.h

@@ -62,9 +62,12 @@ public:
                            nsIAtom* aAttribute,
                            int32_t aModType,
                            const nsAttrValue* aNewValue);
+
+  // XXXbholley: We should assert that the element is already snapshotted.
   void AttributeChanged(dom::Element* aElement, int32_t aNameSpaceID,
                         nsIAtom* aAttribute, int32_t aModType,
-                        const nsAttrValue* aOldValue);
+                        const nsAttrValue* aOldValue) {}
+
   nsresult ReparentStyleContext(nsIFrame* aFrame);
 
   bool HasPendingRestyles() { return !mModifiedElements.IsEmpty(); }