From b9873fa23ed9063e8b3cbb983bca81fbf9d46a36 Mon Sep 17 00:00:00 2001
From: Andreas Pehrson <apehrson@mozilla.com>
Date: Thu, 16 May 2019 06:10:54 +0000
Subject: [PATCH] Bug 1551855 - Add a dedicated pref for enabling GraphRunner.
 r=karlt

Differential Revision: https://phabricator.services.mozilla.com/D31262

--HG--
extra : moz-landing-system : lando
---
 dom/media/MediaStreamGraph.cpp | 4 +++-
 modules/libpref/init/all.js    | 3 +++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/dom/media/MediaStreamGraph.cpp b/dom/media/MediaStreamGraph.cpp
index b49694248253..e320eb04fb7b 100644
--- a/dom/media/MediaStreamGraph.cpp
+++ b/dom/media/MediaStreamGraph.cpp
@@ -3310,7 +3310,9 @@ MediaStreamGraph* MediaStreamGraph::GetInstance(
 
     GraphRunType runType = DIRECT_DRIVER;
     if (aGraphDriverRequested != OFFLINE_THREAD_DRIVER &&
-        Preferences::GetBool("dom.audioworklet.enabled", false)) {
+        (Preferences::GetBool("dom.audioworklet.enabled", false) ||
+         Preferences::GetBool("media.audiograph.single_thread.enabled",
+                              false))) {
       runType = SINGLE_THREAD;
     }
 
diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 23d32e588169..7eca42d7ed7d 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -623,6 +623,9 @@ pref("media.audioipc.stack_size", 262144);
 pref("media.cubeb.sandbox", false);
 #endif
 
+// GraphRunner (fixed MediaStreamGraph thread) control
+pref("media.audiograph.single_thread.enabled", false);
+
 #ifdef MOZ_AV1
 #if defined(XP_WIN) && !defined(_ARM64_)
 pref("media.av1.enabled", true);