Bug fix: stop mirroring session when tab is closed.

content/renderer/media/media_stream_video_capturer_source.cc

 // Copyright 2014 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_video_capturer_source.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
@@ skipping 215 matching lines @@
   // |session_id_| identifies the capture device used for this capture session.
   const media::VideoCaptureSessionId session_id_;
 
   VideoCaptureImplManager* const manager_;
 
   const base::Closure release_device_cb_;
 
   // Indicates if we are capturing generated content, e.g. Tab or Desktop.
   const bool is_content_capture_;
 
-  // This is run once to report whether the device was successfully started
-  // after a call to StartCapture().
+  // These two are valid between StartCapture() and StopCapture().
   RunningCallback running_callback_;

[mcasas, 2016/10/13 13:48:43]

nit: the name is misleading, maybe we could
call if 
StateUpdateCB state_update_callback_; ,
or
IsRunningCallback is_running_callback_;
Doesn't feel entirely right though... I'll be OK
with whatever you do.

[xjz, 2016/10/13 18:11:39]

Yes, the name sounds a little confusing. But it seems that currently only this
LocalVideoCapturerSource uses this callback to notify that when capture stops or
error happens. For other VideoCapturerSource, this callback is just used as a
StartCapture callback. I don't have a better idea for this naming issue. So keep
it as is for now, and add a comment here to explain when it will be called.

-
-  // This is valid between StartCapture() and StopCapture().
   base::Closure stop_capture_cb_;
 
   // Placeholder keeping the callback between asynchronous device enumeration
   // calls.
   VideoCaptureDeviceFormatsCB formats_enumerated_callback_;
 
   // Bound to the main render thread.
   base::ThreadChecker thread_checker_;
 
   base::WeakPtrFactory<LocalVideoCapturerSource> weak_factory_;
@@ skipping 97 matching lines @@
   formats_enumerated_callback_.Reset();
 }
 
 void LocalVideoCapturerSource::OnStateUpdate(VideoCaptureState state) {
   DVLOG(3) << __func__ << " state = " << state;
   DCHECK(thread_checker_.CalledOnValidThread());
   if (running_callback_.is_null())
     return;
   switch (state) {
     case VIDEO_CAPTURE_STATE_STARTED:
-      base::ResetAndReturn(&running_callback_).Run(true);
+      running_callback_.Run(true);
       break;
 
     case VIDEO_CAPTURE_STATE_STOPPING:
     case VIDEO_CAPTURE_STATE_STOPPED:
     case VIDEO_CAPTURE_STATE_ERROR:
     case VIDEO_CAPTURE_STATE_ENDED:
       base::ResetAndReturn(&running_callback_).Run(false);
       break;
 
     case VIDEO_CAPTURE_STATE_PAUSED:
@@ skipping 126 matching lines @@
 void MediaStreamVideoCapturerSource::OnStarted(bool result) {
   OnStartDone(result ? MEDIA_DEVICE_OK : MEDIA_DEVICE_TRACK_START_FAILURE);
 }
 
 const char*
 MediaStreamVideoCapturerSource::GetPowerLineFrequencyForTesting() const {
   return kPowerLineFrequency;
 }
 
 }  // namespace content