Tentatively turn on WebMediaPlayerMS by default.

content/renderer/media/media_stream_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/media/media_stream_impl.h"
 
 #include <utility>
 
 #include "base/logging.h"
 #include "base/string_number_conversions.h"
@@ skipping 128 matching lines @@
     user_media_requests_.erase(it);
   }
 }
 
 WebKit::WebMediaStreamDescriptor MediaStreamImpl::GetMediaStream(
     const GURL& url) {
   return WebKit::WebMediaStreamRegistry::lookupMediaStreamDescriptor(url);
 }
 
 bool MediaStreamImpl::IsMediaStream(const GURL& url) {
-  DCHECK(CalledOnValidThread());
-  WebKit::WebMediaStreamDescriptor descriptor(GetMediaStream(url));
+  return CheckMediaStream(url);
+}
+
+// static
+bool MediaStreamImpl::CheckMediaStream(const GURL& url) {
+  WebKit::WebMediaStreamDescriptor descriptor(
+      WebKit::WebMediaStreamRegistry::lookupMediaStreamDescriptor(url));
 
   if (descriptor.isNull() || !descriptor.extraData())
     return false;  // This is not a valid stream.
 
   MediaStreamExtraData* extra_data =
       static_cast<MediaStreamExtraData*>(descriptor.extraData());
   webrtc::MediaStreamInterface* stream = extra_data->local_stream();
   if (stream && stream->video_tracks() && stream->video_tracks()->count() > 0)
     return true;
   stream = extra_data->remote_stream();
@@ skipping 295 matching lines @@
 
 void MediaStreamExtraData::SetLocalStreamStopCallback(
     const StreamStopCallback& stop_callback) {
   stream_stop_callback_ = stop_callback;
 }
 
 void MediaStreamExtraData::OnLocalStreamStop() {
   if (!stream_stop_callback_.is_null())
     stream_stop_callback_.Run(local_stream_->label());
 }