[chromecast] Disable WebM, Vorbis tests for ALSA

chromecast/chromecast_tests.gypi

Index: chromecast/chromecast_tests.gypi
diff --git a/chromecast/chromecast_tests.gypi b/chromecast/chromecast_tests.gypi
index 5f9aa93921bd7c3da7ab0282d5c04585520ebd31..08efa7dcd60583a182fcc015b4950444415c0d68 100644
--- a/chromecast/chromecast_tests.gypi
+++ b/chromecast/chromecast_tests.gypi
@@ -122,6 +122,14 @@
             ],
           },
         }],
+        ['disable_display==1', {
+          'variables': {
+            'filters': [
+              # These are not supported by the backend right now. b/21737919
+              'cast_media_unittests --gtest_filter=-AudioVideoPipelineDeviceTest.VorbisPlayback:AudioVideoPipelineDeviceTest.WebmPlayback',
+            ],
+          }
+        }],
       ],
       'includes': ['build/tests/test_list.gypi'],
     },