VideoTrackAdapter: Add passing frames monitor, notify MSVCS -> MSVTrack(s)

content/renderer/media/media_stream_video_source.cc

Index: content/renderer/media/media_stream_video_source.cc
diff --git a/content/renderer/media/media_stream_video_source.cc b/content/renderer/media/media_stream_video_source.cc
index 45c6abd7aa0fac26d14760a3ee48f149bf1d8b4d..26b1e22a2ba7610d1450c7c6b3aea613fa45c573 100644
--- a/content/renderer/media/media_stream_video_source.cc
+++ b/content/renderer/media/media_stream_video_source.cc
@@ -15,6 +15,7 @@
 #include "content/renderer/media/media_stream_constraints_util.h"
 #include "content/renderer/media/media_stream_video_track.h"
 #include "content/renderer/media/video_track_adapter.h"
+#include "media/base/bind_to_current_loop.h"
 
 namespace content {
 
@@ -350,6 +351,7 @@ bool MediaStreamVideoSource::IsConstraintSupported(const std::string& name) {
 
 MediaStreamVideoSource::MediaStreamVideoSource()
     : state_(NEW),
+      muted_state_(false),
       track_adapter_(new VideoTrackAdapter(
           ChildProcess::current()->io_message_loop_proxy())),
       weak_factory_(this) {
@@ -552,10 +554,16 @@ void MediaStreamVideoSource::FinalizeAddTrack() {
       double max_frame_rate = 0.0f;
       GetConstraintValueAsDouble(it->constraints,
                                  kMaxFrameRate, &max_frame_rate);
+
+      // QUESTION(mcasas): is Unretained OK here?

[Henrik Grunell, 2014/07/08 11:39:53]

Does this MediaStreamVideoSource object outlive the thread
MediaStreamVideoSource::SetMutedState is called on? If so, yes.

Does this MediaStreamVideoSource object outlive |track_adapter_|? If so, yes.

Otherwise, afaict, no.

[mcasas, 2014/07/08 16:12:01]

MSVS has a |weak_ptr_factory_|, never mind this.

[Henrik Grunell, 2014/07/09 08:55:52]

How/where is a weak ptr used to ensure we don't callback to a deleted object?

[mcasas, 2014/07/09 12:39:35]

"You can use a base::WeakPtr and base::WeakPtrFactory (in
base/memory/weak_ptr.h) to ensure that any invokes can not outlive the object
they are being invoked on, without using reference counting. The base::Bind
mechanism has special understanding for base::WeakPtr that will disable the
task's execution if the base::WeakPtr has been invalidated. " [1]

[1]
http://www.chromium.org/developers/design-documents/threading#base_WeakPtr_an...

[Henrik Grunell, 2014/07/09 13:01:22]

Yes. But you need to change base::Unretained(this) to
weak_ptr_factory_.GetWeakPtr(). (Sorry if I wasn't explicit before.) I saw you
made that change now.

+      VideoTrackAdapter::OnMutedCallback on_mute_callback =
+          media::BindToCurrentLoop(base::Bind(
+              &MediaStreamVideoSource::SetMutedState, base::Unretained(this)));
       track_adapter_->AddTrack(it->track, it->frame_callback,
                                max_width, max_height,
                                min_aspect_ratio, max_aspect_ratio,
-                               max_frame_rate);
+                               max_frame_rate, current_format_.frame_rate,
+                               on_mute_callback);
     }
 
     DVLOG(3) << "FinalizeAddTrack() success " << success;
@@ -577,6 +585,16 @@ void MediaStreamVideoSource::SetReadyState(
   }
 }
 
+void MediaStreamVideoSource::SetMutedState(bool muted_state) {
+  DCHECK(CalledOnValidThread());
+  DVLOG(3) << "MediaStreamVideoSource::SetBoolState state " << muted_state;
+  // WebMediaStreamSource doesn't have a muted state, the tracks do.
+  for (std::vector<MediaStreamVideoTrack*>::iterator it = tracks_.begin();
+       it != tracks_.end(); ++it) {
+    (*it)->SetMutedState(muted_state);
+  }
+}
+
 MediaStreamVideoSource::RequestedConstraints::RequestedConstraints(
     MediaStreamVideoTrack* track,
     const VideoCaptureDeliverFrameCB& frame_callback,