Bug 1191833: P2. Update webref test expected results. r=karlt

Video codecs aren't allowed in an audio container.

testing/web-platform/meta/media-source/mediasource-is-type-supported.html.ini

@@ -29,13 +29,6 @@
     bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1191833
     expected: FAIL
 
-  [Test invalid mismatch between major type and codec ID "audio/webm;codecs="vp8""]
-    bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1191833
-    expected: FAIL
-
-  [Test valid MP4 type "audio/mp4;codecs="mp4a.67""]
-    expected: FAIL
-
   [Test valid MP4 type "video/mp4;codecs="avc1.4d001e""]
     expected:
       if (os == "win") and (version == "5.1.2600"): FAIL