From 92d38d1e222f53241d74827b7816effa7f3253b0 Mon Sep 17 00:00:00 2001
From: Ali Juma <ajuma@mozilla.com>
Date: Wed, 14 Mar 2012 10:54:34 -0400
Subject: [PATCH] Bug 735600 - Don't composite when the layer tree is empty.
 r=bgirard

---
 gfx/layers/ipc/CompositorParent.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gfx/layers/ipc/CompositorParent.cpp b/gfx/layers/ipc/CompositorParent.cpp
index e1fbb0277596..108b0493f49a 100644
--- a/gfx/layers/ipc/CompositorParent.cpp
+++ b/gfx/layers/ipc/CompositorParent.cpp
@@ -185,7 +185,7 @@ CompositorParent::Composite()
 
   mLastCompose = mozilla::TimeStamp::Now();
 
-  if (mPaused || !mLayerManager) {
+  if (mPaused || !mLayerManager || !mLayerManager->GetRoot()) {
     return;
   }