Bug 852049 - [Audio] The default value of Master Volume should be 1.0 if settings don't set a value. r=mwu

b2g/chrome/content/settings.js

@@ -63,7 +63,7 @@ var SettingsListener = {
 SettingsListener.init();
 
 // =================== Audio ====================
-SettingsListener.observe('audio.volume.master', 0.5, function(value) {
+SettingsListener.observe('audio.volume.master', 1.0, function(value) {
   let audioManager = Services.audioManager;
   if (!audioManager)
     return;