Bug 567944. Work around inefficiency in handling eRestyle_LaterSiblings for now. r=dbaron

layout/base/nsCSSFrameConstructor.cpp

@@ -11410,14 +11410,11 @@ static void
 RestyleSiblingsStartingWith(nsCSSFrameConstructor *aFrameConstructor,
                             nsIContent *aStartingSibling /* may be null */)
 {
-  for (nsIContent *sibling = aStartingSibling; sibling;
-       sibling = sibling->GetNextSibling()) {
-    if (sibling->IsElement()) {
-      aFrameConstructor->
-        PostRestyleEvent(sibling->AsElement(),
-                         nsRestyleHint(eRestyle_Self | eRestyle_LaterSiblings),
+  if (aStartingSibling) {
+    nsIContent* parent = aStartingSibling->GetParent();
+    if (parent && parent->IsElement()) {
+      aFrameConstructor->PostRestyleEvent(parent->AsElement(), eRestyle_Self,
                                           NS_STYLE_HINT_NONE);
-      break;
     }
   }
 }