Show audio as enabled when an audio track is present in stream

dom/html/HTMLMediaElement.cpp

@@ -3490,6 +3490,12 @@ void HTMLMediaElement::UpdateReadyStateForData(MediaDecoderOwner::NextFrameStatu
     // We are playing a stream that has video and a video frame is now set.
     // This means we have all metadata needed to change ready state.
     MediaInfo mediaInfo = mMediaInfo;
+    if (hasAudio) {
+      mediaInfo.EnableAudio();
+    }
+    if (hasVideo) {
+      mediaInfo.EnableVideo();
+    }
     MetadataLoaded(&mediaInfo, nsAutoPtr<const MetadataTags>(nullptr));
   }