Bug 888836 - Turn off audio channels for non apps. r=mfinkle

mobile/android/app/mobile.js

@@ -749,8 +749,8 @@ pref("dom.payment.provider.0.type", "mozilla/payments/pay/v1");
 pref("dom.payment.provider.0.requestMethod", "GET");
 #endif
 
-// Make <audio> and <video> talk to the AudioChannelService.
-pref("media.useAudioChannelService", true);
+// Support for the mozAudioChannel attribute on media elements is disabled in non-webapps
+pref("media.useAudioChannelService", false);
 
 // Turn on the CSP 1.0 parser for Content Security Policy headers
 pref("security.csp.speccompliant", true);

mobile/android/chrome/content/WebAppRT.js

@@ -29,7 +29,8 @@ let WebAppRT = {
     pref("xpinstall.enabled", false),
     // Set a future policy version to avoid the telemetry prompt.
     pref("toolkit.telemetry.prompted", 999),
-    pref("toolkit.telemetry.notifiedOptOut", 999)
+    pref("toolkit.telemetry.notifiedOptOut", 999),
+    pref("media.useAudioChannelService", true);
   ],
 
   init: function(aStatus, aUrl, aCallback) {