Bug 1536604 - disable manifest dom/media/test/mochitest.ini r=jmaher

Disable the following:

- test_MediaSource_flac_mp4 (keeps getting missed somehow)
- dom/media/test/mochitest.ini

Disabling the entire `dom/media/test/mochitest.ini` manifest file does have collateral damage in that it disables tests that are running fine; the alternative is to disable only the EME tests, but the failure count numbers somewhere close to 50.

Differential Revision: https://phabricator.services.mozilla.com/D24094

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

dom/media/mediasource/test/mochitest.ini

@@ -105,6 +105,7 @@ skip-if = android_version == '22' # bug 1225758
 [test_MediaSource_mp4.html]
 skip-if = toolkit == 'android' # Not supported on android
 [test_MediaSource_flac_mp4.html]
+skip-if = (os == "win" && processor == "aarch64") # aarch64 due to 1526064
 [test_MediaSource_disabled.html]
 [test_MultipleInitSegments.html]
 [test_MultipleInitSegments_mp4.html]

dom/media/test/mochitest.ini

@@ -23,7 +23,7 @@
 
 [DEFAULT]
 subsuite = media
-skip-if = android_version == '18' # Run on real devices via autophone
+skip-if = android_version == '18' || (os == "win" && processor == "aarch64") # Run on real devices via autophone, aarch64 due to 1536604
 support-files =
   16bit_wave_extrametadata.wav
   16bit_wave_extrametadata.wav^headers^