Bug 1231485 part 2 - Add NeutralChange hint to nsStyleText::MaxDifference(). r=dbaron

--HG--
extra : source : e52efce3dce402c1d73790cba33d0a756c3604a9

layout/style/nsStyleStruct.h

@@ -1746,7 +1746,8 @@ struct nsStyleText {
   nsChangeHint CalcDifference(const nsStyleText& aOther) const;
   static nsChangeHint MaxDifference() {
     return NS_STYLE_HINT_FRAMECHANGE |
-           nsChangeHint_UpdateSubtreeOverflow;
+           nsChangeHint_UpdateSubtreeOverflow |
+           nsChangeHint_NeutralChange;
   }
   static nsChangeHint DifferenceAlwaysHandledForDescendants() {
     // CalcDifference never returns the reflow hints that are sometimes