Bug 566777: nsSMILMappedAttribute::ClearAnimValue shouldn't do anything if there's no animated value to clear. r=roc

content/smil/nsSMILMappedAttribute.cpp

@@ -145,12 +145,11 @@ nsSMILMappedAttribute::ClearAnimValue()
 {
   nsRefPtr<nsIAtom> attrName = GetAttrNameAtom();
   nsresult rv = mElement->DeleteProperty(SMIL_MAPPED_ATTR_ANIMVAL, attrName);
-  if (NS_FAILED(rv)) {
-    // XXXdholbert Can this ever happen? Leaving this warning for now, to
-    // see if we ever trigger this.
-    NS_WARNING("couldn't clear animated value (perhaps it wasn't set?)");
+  if (NS_SUCCEEDED(rv)) {
+    FlushChangesToTargetAttr();
   }
-  FlushChangesToTargetAttr();
+  // Else, there's no animated value to be cleared -- no need to flush
+  // changes, because we didn't change anything.
 }
 
 void