--- a/dom/base/Element.cpp
+++ b/dom/base/Element.cpp
@@ -1949,22 +1949,17 @@ Element::SetSMILOverrideStyleDeclaration
   if (aNotify) {
     nsIDocument* doc = GetComposedDoc();
     // Only need to request a restyle if we're in a document.  (We might not
     // be in a document, if we're clearing animation effects on a target node
     // that's been detached since the previous animation sample.)
     if (doc) {
       nsCOMPtr<nsIPresShell> shell = doc->GetShell();
       if (shell) {
-        // Pass both eRestyle_StyleAttribute and
-        // eRestyle_StyleAttribute_Animations since we don't know if
-        // this style represents only the ticking of an existing
-        // animation or whether it's a new or changed animation.
-        shell->RestyleForAnimation(this, eRestyle_StyleAttribute |
-                                         eRestyle_StyleAttribute_Animations);
+        shell->RestyleForAnimation(this, eRestyle_StyleAttribute_Animations);
       }
     }
   }
 
   return NS_OK;
 }
 
 bool