From f1f06de017938b4258ff46758c672b33f72bbd69 Mon Sep 17 00:00:00 2001
From: Bas Schouten <bschouten@mozilla.com>
Date: Wed, 12 May 2010 20:56:31 +0200
Subject: [PATCH] Bug 565387: Add a pref to disable accelerated layers by
 force. r=vlad

---
 modules/libpref/src/init/all.js       |  3 +++
 widget/src/xpwidgets/nsBaseWidget.cpp | 10 +++++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/modules/libpref/src/init/all.js b/modules/libpref/src/init/all.js
index de1ad75a92c..451fa571540 100644
--- a/modules/libpref/src/init/all.js
+++ b/modules/libpref/src/init/all.js
@@ -2808,6 +2808,9 @@ pref("gfx.color_management.mode", 0);
 // Initialize default render-mode.
 pref("mozilla.widget.render-mode", -1);
 
+// Initialize default accelerated layers
+pref("mozilla.widget.accelerated-layers", true);
+
 // Enable/Disable the geolocation API for content
 pref("geo.enabled", true);
 
diff --git a/widget/src/xpwidgets/nsBaseWidget.cpp b/widget/src/xpwidgets/nsBaseWidget.cpp
index 01998397f34..17c05316f38 100644
--- a/widget/src/xpwidgets/nsBaseWidget.cpp
+++ b/widget/src/xpwidgets/nsBaseWidget.cpp
@@ -661,7 +661,15 @@ nsBaseWidget::AutoLayerManagerSetup::~AutoLayerManagerSetup()
 LayerManager* nsBaseWidget::GetLayerManager()
 {
   if (!mLayerManager) {
-    if (mUseAcceleratedRendering) {
+    nsCOMPtr<nsIPrefBranch2> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
+
+    PRBool allowAcceleration = PR_TRUE;
+    if (prefs) {
+      prefs->GetBoolPref("mozilla.widget.accelerated-layers",
+                         &allowAcceleration);
+    }
+
+    if (mUseAcceleratedRendering && allowAcceleration) {
       nsRefPtr<LayerManagerOGL> layerManager =
         new mozilla::layers::LayerManagerOGL(this);
       /**