Bug 1590249 - Enable AudioIPC on Windows in Nightly builds. r=chunmin

Differential Revision: https://phabricator.services.mozilla.com/D60618

--HG--
extra : moz-landing-system : lando

modules/libpref/init/StaticPrefList.yaml

@@ -5877,6 +5877,8 @@
   mirror: always
 #if defined(XP_LINUX) && !defined(MOZ_WIDGET_ANDROID)
   value: true
+#elif defined(XP_WIN) && !defined(_ARM64_)
+  value: @IS_NIGHTLY_BUILD@
 #else
   value: false
 #endif

toolkit/content/tests/browser/browser.ini

@@ -1,6 +1,7 @@
 [DEFAULT]
 prefs =
   plugin.load_flash_only=false
+  media.cubeb.sandbox=false # BMO 1610640
 support-files =
   almostSilentAudioTrack.webm
   audio.ogg