Bug 1767582 - Enable Utility AudioDecoder on Nightly r=alwu

Differential Revision: https://phabricator.services.mozilla.com/D145584

ipc/glue/test/browser/browser_utility_multipleAudio.js

@@ -8,9 +8,13 @@ async function runTest(expectUtility) {
     `Running tests with decoding from Utility or RDD: expectUtility=${expectUtility}`
   );
 
-  await SpecialPowers.pushPrefEnv({
-    set: [["media.utility-process.enabled", expectUtility]],
-  });
+  // Utility should now be the default, so dont toggle the pref unless we test
+  // RDD
+  if (!expectUtility) {
+    await SpecialPowers.pushPrefEnv({
+      set: [["media.utility-process.enabled", expectUtility]],
+    });
+  }
 
   for (let src of [
     "small-shot.ogg",

modules/libpref/init/StaticPrefList.yaml

@@ -8909,9 +8909,21 @@
 # using the IPC actor within the Utility process rather than the RDD process.
 # When it is set to true, then the utility process will take precedence over RDD
 # to perform audio decoding.
+# TODO: Android: Bug 1767930
+# TODO: OpenBSD: Bug 1769033
 - name: media.utility-process.enabled
   type: RelaxedAtomicBool
+#if defined(XP_WIN)
+  value: true
+#elif defined(XP_MACOSX)
+  value: true
+#elif defined(XP_LINUX) && !defined(ANDROID)
+  value: true
+#elif defined(XP_OPENBSD)
   value: false
+#else
+  value: false
+#endif
   mirror: always
 
 #ifdef MOZ_FFMPEG