Bug 793315 - Test single tag metadata. r=cpearce

Verify that we return metadata tags from streams with only a
single comment by adding a single comment to a file which
previously had none.

This bug went undetected because all our examples had either
multiple tags, or none.

content/media/test/manifest.js

@@ -352,6 +352,10 @@ var gMetadataTests = [
     }
   },
   { name:"sound.ogg", tags: { } },
+  { name:"small-shot.ogg", tags: {
+      title:"Pew SFX"
+    }
+  },
   { name:"badtags.ogg", tags: {
       // We list only the valid tags here, and verify
       // the invalid ones are filtered out.