Bug 1598101 - disable test_mediarecorder_record_4ch_audiocontext.html on linux64 r=jmaher

Differential Revision: https://phabricator.services.mozilla.com/D54439

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

dom/media/test/mochitest.ini

@@ -895,6 +895,7 @@ skip-if = (os == 'win' && os_version == '10.0' && webrender) # Bug 1453375
 tags=mtg
 [test_mediarecorder_record_4ch_audiocontext.html]
 tags=mtg
+skip-if = os == "linux" && bits == 64 #Bug 1598101
 [test_mediarecorder_record_addtracked_stream.html]
 skip-if = toolkit == 'android' # Bug 1408241
 tags=mtg capturestream