From 4dbc15ef1a74b02d712b69aa82b84074336097d7 Mon Sep 17 00:00:00 2001
From: Robert O'Callahan <robert@ocallahan.org>
Date: Wed, 4 Sep 2013 16:43:33 +1200
Subject: [PATCH] Bug 911889. Part 1: Fix mutationUpdate mutation count for
 first as well as subsequent mutations. r=benwa

---
 layout/generic/nsFrame.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/layout/generic/nsFrame.cpp b/layout/generic/nsFrame.cpp
index fcf32237a866..3d5465af0a0a 100644
--- a/layout/generic/nsFrame.cpp
+++ b/layout/generic/nsFrame.cpp
@@ -4570,7 +4570,6 @@ nsIFrame::MarkLayersActive(nsChangeHint aChangeHint)
     static_cast<LayerActivity*>(properties.Get(LayerActivityProperty()));
   if (layerActivity) {
     gLayerActivityTracker->MarkUsed(layerActivity);
-    layerActivity->mMutationCount++;
   } else {
     if (!gLayerActivityTracker) {
       gLayerActivityTracker = new LayerActivityTracker();
@@ -4579,6 +4578,7 @@ nsIFrame::MarkLayersActive(nsChangeHint aChangeHint)
     gLayerActivityTracker->AddObject(layerActivity);
     properties.Set(LayerActivityProperty(), layerActivity);
   }
+  layerActivity->mMutationCount++;
   NS_UpdateHint(layerActivity->mChangeHint, aChangeHint);
 }