Bug 1401909 - turn on preference of ShutdownDecoder feature on desktop version release and beta channel; r=bwu

MozReview-Commit-ID: JB3RmyjhvK9

--HG--
extra : rebase_source : 96e93ab111799910f03d9cac3bd3ac5084e40f07

modules/libpref/init/all.js

@@ -432,11 +432,7 @@ pref("media.decoder-doctor.wmf-disabled-is-failure", false);
 pref("media.decoder-doctor.new-issue-endpoint", "https://webcompat.com/issues/new");
 
 // Whether to suspend decoding of videos in background tabs.
-#ifdef RELEASE_OR_BETA
-pref("media.suspend-bkgnd-video.enabled", false);
-#else
 pref("media.suspend-bkgnd-video.enabled", true);
-#endif
 // Delay, in ms, from time window goes to background to suspending
 // video decoders. Defaults to 10 seconds.
 pref("media.suspend-bkgnd-video.delay-ms", 10000);