fix(MediaCap): Fix VP9 codec unit test

Change-Id: I7d82cb3dcb01be702dcbc9084df55c8db9493b58

Author: michellezhuogg

test/util/stream_utils_unit.js

@@ -635,6 +635,9 @@ describe('StreamUtils', () => {
     });
 
     it('supports VP9 codec', async () => {
+      if (!MediaSource.isTypeSupported('video/webm; codecs="vp9"')) {
+        pending('Codec VP9 is not supported by the platform.');
+      }
       manifest = shaka.test.ManifestGenerator.generate((manifest) => {
         manifest.addVariant(0, (variant) => {
           variant.addVideo(1, (stream) => {
@@ -646,6 +649,7 @@ describe('StreamUtils', () => {
       await shaka.util.StreamUtils.filterManifest(
           fakeDrmEngine, /* currentVariant= */ null, manifest,
           /* useMediaCapabilities= */ true);
+
       expect(manifest.variants.length).toBe(1);
     });
   });