From 2d4bc1d4acee012bebbcb1d8360c3e38588c9792 Mon Sep 17 00:00:00 2001
From: Blake Kaplan <mrbkap@gmail.com>
Date: Mon, 8 Feb 2016 14:51:00 +0100
Subject: [PATCH] Bug 1176449 - Enter an update here to avoid assertions on
 startup. r=dbaron

--HG--
extra : rebase_source : 333672b991d5ad0c38b9516375366dd69f528d03
---
 dom/xul/XULDocument.cpp | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/dom/xul/XULDocument.cpp b/dom/xul/XULDocument.cpp
index dc6414fd26e3..d391a90b0da2 100644
--- a/dom/xul/XULDocument.cpp
+++ b/dom/xul/XULDocument.cpp
@@ -92,6 +92,7 @@
 #include "nsJSUtils.h"
 #include "mozilla/dom/URL.h"
 #include "nsIContentPolicy.h"
+#include "mozAutoDocUpdate.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;
@@ -2967,10 +2968,14 @@ XULDocument::DoneWalking()
     // XXXldb This is where we should really be setting the chromehidden
     // attribute.
 
-    uint32_t count = mOverlaySheets.Length();
-    for (uint32_t i = 0; i < count; ++i) {
-        AddStyleSheet(mOverlaySheets[i]);
+    {
+        mozAutoDocUpdate updateBatch(this, UPDATE_STYLE, true);
+        uint32_t count = mOverlaySheets.Length();
+        for (uint32_t i = 0; i < count; ++i) {
+            AddStyleSheet(mOverlaySheets[i]);
+        }
     }
+
     mOverlaySheets.Clear();
 
     if (!mDocumentLoaded) {