Bug 1243857 - Enable duplex audio for OSX. r=jesup

MozReview-Commit-ID: LEYhxK3xhed

modules/libpref/init/all.js

@@ -442,7 +442,7 @@ pref("media.getusermedia.agc", 1);
 #if defined(XP_MACOSX)
 pref("media.peerconnection.capture_delay", 50);
 pref("media.getusermedia.playout_delay", 10);
-pref("media.navigator.audio.full_duplex", false);
+pref("media.navigator.audio.full_duplex", true);
 #elif defined(XP_WIN)
 pref("media.peerconnection.capture_delay", 50);
 pref("media.getusermedia.playout_delay", 40);