Allow MediaRecorder to record Muted streams

content/renderer/media/media_recorder_handler.cc

Index: content/renderer/media/media_recorder_handler.cc
diff --git a/content/renderer/media/media_recorder_handler.cc b/content/renderer/media/media_recorder_handler.cc
index 4bc45a0c9faa0524c134ee9b683beb57dec7f7d9..46dc73625fc727b5db039af94227cd5221201446 100644
--- a/content/renderer/media/media_recorder_handler.cc
+++ b/content/renderer/media/media_recorder_handler.cc
@@ -167,15 +167,15 @@ bool MediaRecorderHandler::start(int timeslice) {
     return false;
   }
 
-  const bool use_video_tracks = !video_tracks.isEmpty() &&
-                                video_tracks[0].isEnabled() &&
-                                video_tracks[0].source().getReadyState() ==
-                                    blink::WebMediaStreamSource::ReadyStateLive;
-  const bool use_audio_tracks = !audio_tracks.isEmpty() &&
-                                MediaStreamAudioTrack::From(audio_tracks[0]) &&
-                                audio_tracks[0].isEnabled() &&
-                                audio_tracks[0].source().getReadyState() ==
-                                    blink::WebMediaStreamSource::ReadyStateLive;
+  const bool use_video_tracks =
+      !video_tracks.isEmpty() && video_tracks[0].isEnabled() &&
+      video_tracks[0].source().getReadyState() !=
+          blink::WebMediaStreamSource::ReadyStateEnded;
+  const bool use_audio_tracks =
+      !audio_tracks.isEmpty() && MediaStreamAudioTrack::From(audio_tracks[0]) &&
+      audio_tracks[0].isEnabled() &&
+      audio_tracks[0].source().getReadyState() !=
+          blink::WebMediaStreamSource::ReadyStateEnded;
 
   webm_muxer_.reset(new media::WebmMuxer(
       CodecIdToMediaVideoCodec(codec_id_), use_video_tracks, use_audio_tracks,