Bug 911310 - Only raise an nsChangeHint_UpdateOverflow for filters. r=dholbert

layout/style/nsStyleStruct.cpp

@@ -1150,11 +1150,16 @@ nsChangeHint nsStyleSVGReset::CalcDifference(const nsStyleSVGReset& aOther) cons
 {
   nsChangeHint hint = nsChangeHint(0);
 
+  bool equalFilters = (mFilters == aOther.mFilters);
+
+  if (!equalFilters) {
+    NS_UpdateHint(hint, nsChangeHint_UpdateOverflow);
+  }
+
   if (!EqualURIs(mClipPath, aOther.mClipPath) ||
       !EqualURIs(mMask, aOther.mMask) ||
-      mFilters != aOther.mFilters) {
+      !equalFilters) {
     NS_UpdateHint(hint, nsChangeHint_UpdateEffects);
-    NS_UpdateHint(hint, nsChangeHint_UpdateOverflow); // for filters only
     NS_UpdateHint(hint, nsChangeHint_RepaintFrame);
   }