[Mojo Video Capture] Stop service when last client disconnects.

services/video_capture/receiver_mojo_to_media_adapter.h

 // Copyright 2016 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.
 
 #ifndef SERVICES_VIDEO_CAPTURE_RECEIVER_MOJO_TO_MEDIA_ADAPTER_H_
 #define SERVICES_VIDEO_CAPTURE_RECEIVER_MOJO_TO_MEDIA_ADAPTER_H_
 
 #include "media/capture/video/video_frame_receiver.h"
 #include "services/video_capture/public/interfaces/receiver.mojom.h"
 
 namespace video_capture {
 
+class ReceiverOnTaskRunner : public media::VideoFrameReceiver {
+ public:
+  ReceiverOnTaskRunner(std::unique_ptr<media::VideoFrameReceiver> receiver,
+                       scoped_refptr<base::SingleThreadTaskRunner> task_runner);
+  ~ReceiverOnTaskRunner() override;
+
+  // media::VideoFrameReceiver:

[mcasas, 2017/04/26 22:12:31]

nit: this is written customarily as:
// media::VideoFrameReceiver implementation.

[chfremer, 2017/04/26 23:33:36]

Done.

+  void OnNewBufferHandle(
+      int buffer_id,
+      std::unique_ptr<media::VideoCaptureDevice::Client::Buffer::HandleProvider>
+          handle_provider) override;
+  void OnFrameReadyInBuffer(
+      int buffer_id,
+      int frame_feedback_id,
+      std::unique_ptr<
+          media::VideoCaptureDevice::Client::Buffer::ScopedAccessPermission>
+          buffer_read_permission,
+      media::mojom::VideoFrameInfoPtr frame_info) override;
+  void OnBufferRetired(int buffer_id) override;
+  void OnError() override;
+  void OnLog(const std::string& message) override;
+  void OnStarted() override;
+  void OnStartedUsingGpuDecode() override;
+
+ private:
+  std::unique_ptr<media::VideoFrameReceiver> receiver_;
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;

[mcasas, 2017/04/26 22:12:31]

const.

[chfremer, 2017/04/26 23:33:36]

Done.

+};
+
 // Adapter that allows a mojom::VideoFrameReceiver to be used in place of
 // a media::VideoFrameReceiver.
 class ReceiverMojoToMediaAdapter : public media::VideoFrameReceiver {
  public:
   ReceiverMojoToMediaAdapter(mojom::ReceiverPtr receiver);
   ~ReceiverMojoToMediaAdapter() override;
 
+  void ResetConnectionErrorHandler();

[mcasas, 2017/04/26 22:12:31]

const method?

[chfremer, 2017/04/26 23:33:36]

Not possible here, because it requires non-const access to member |receiver_|.

+
   // media::VideoFrameReceiver:

[mcasas, 2017/04/26 22:12:31]

nit: // media::VideoFrameReceiver implementation.

I counted how many such cases there are in content:

grep -rn "implementation\." `find content/ | grep '\.h' ` | grep "//" | wc -l
     527

[chfremer, 2017/04/26 23:33:36]

Done.

   void OnNewBufferHandle(
       int buffer_id,
       std::unique_ptr<media::VideoCaptureDevice::Client::Buffer::HandleProvider>
           handle_provider) override;
   void OnFrameReadyInBuffer(
       int buffer_id,
       int frame_feedback_id,
       std::unique_ptr<
           media::VideoCaptureDevice::Client::Buffer::ScopedAccessPermission>
           access_permission,
       media::mojom::VideoFrameInfoPtr frame_info) override;
   void OnBufferRetired(int buffer_id) override;
   void OnError() override;
   void OnLog(const std::string& message) override;
   void OnStarted() override;
   void OnStartedUsingGpuDecode() override;
 
  private:
   mojom::ReceiverPtr receiver_;
 };
 
 }  // namespace video_capture
 
 #endif  // SERVICES_VIDEO_CAPTURE_RECEIVER_MOJO_TO_MEDIA_ADAPTER_H_