Bug 1383610 - turn off preference of ShutdownDecoder feature on desktop version release and beta channel but keep the Fennec on; r=bwu

MozReview-Commit-ID: 38RLaR3Vxeh

--HG--
extra : rebase_source : 508fd63ff8db1445be8fb1f3b286311fabc888bd

modules/libpref/init/all.js

@@ -444,7 +444,7 @@ 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
+#ifdef RELEASE_OR_BETA
 pref("media.suspend-bkgnd-video.enabled", false);
 #else
 pref("media.suspend-bkgnd-video.enabled", true);