From ae799e322ac20e44c8f509765b06891a407850de Mon Sep 17 00:00:00 2001
From: Anthony Jones <ajones@mozilla.com>
Date: Wed, 27 Mar 2013 11:25:12 +1300
Subject: [PATCH] Bug 852251 - Check for null on CompositorChild::Get()

---
 dom/ipc/TabChild.cpp | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/dom/ipc/TabChild.cpp b/dom/ipc/TabChild.cpp
index 9ec4a1f4631..50e0877ad32 100644
--- a/dom/ipc/TabChild.cpp
+++ b/dom/ipc/TabChild.cpp
@@ -2104,10 +2104,15 @@ TabChild::InitRenderingState()
     if (id != 0) {
         // Pushing layers transactions directly to a separate
         // compositor context.
+        PCompositorChild* compositorChild = CompositorChild::Get();
+        if (!compositorChild) {
+          NS_WARNING("failed to get CompositorChild instance");
+          return false;
+        }
         shadowManager =
-            CompositorChild::Get()->SendPLayersConstructor(be, id,
-                                                           &be,
-                                                           &maxTextureSize);
+            compositorChild->SendPLayersConstructor(be, id,
+                                                    &be,
+                                                    &maxTextureSize);
     } else {
         // Pushing transactions to the parent content.
         shadowManager = remoteFrame->SendPLayersConstructor();