Bug 1308115 - set the pref media.ondevicechange.enabled default true; r=jesup

MozReview-Commit-ID: 1WusFq1n5oh

--HG--
extra : rebase_source : 77e182c6c97da85332b4bab872c379d90bc99fde

modules/libpref/init/all.js

@@ -4825,7 +4825,7 @@ pref("dom.w3c_pointer_events.implicit_capture", false);
 pref("dom.imagecapture.enabled", false);
 
 // W3C MediaDevices devicechange event
-pref("media.ondevicechange.enabled", false);
+pref("media.ondevicechange.enabled", true);
 
 // W3C MediaDevices devicechange fake event
 pref("media.ondevicechange.fakeDeviceChangeEvent.enabled", false);