From f9eaee1ae04971dd9b076c8a5446c2df68e0e003 Mon Sep 17 00:00:00 2001
From: Benoit Girard <b56girard@gmail.com>
Date: Mon, 5 Mar 2012 14:02:22 -0500
Subject: [PATCH] Bug 717958 - Always read FPS pref on the main thread with
 OMTC. r=ajuma

---
 gfx/layers/opengl/LayerManagerOGL.cpp | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/gfx/layers/opengl/LayerManagerOGL.cpp b/gfx/layers/opengl/LayerManagerOGL.cpp
index 6cf649e0252..31bd86054b1 100644
--- a/gfx/layers/opengl/LayerManagerOGL.cpp
+++ b/gfx/layers/opengl/LayerManagerOGL.cpp
@@ -367,7 +367,20 @@ LayerManagerOGL::Initialize(nsRefPtr<GLContext> aContext, bool force)
     console->LogStringMessage(msg.get());
   }
 
-  Preferences::AddBoolVarCache(&sDrawFPS, "layers.acceleration.draw-fps");
+  if (NS_IsMainThread()) {
+    Preferences::AddBoolVarCache(&sDrawFPS, "layers.acceleration.draw-fps");
+  } else {
+    // We have to dispatch an event to the main thread to read the pref.
+    class ReadDrawFPSPref : public nsRunnable {
+    public:
+      NS_IMETHOD Run()
+      {
+        Preferences::AddBoolVarCache(&sDrawFPS, "layers.acceleration.draw-fps");
+        return NS_OK;
+      }
+    };
+    NS_DispatchToMainThread(new ReadDrawFPSPref());
+  }
 
   reporter.SetSuccessful();
   return true;