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

services/video_capture/device_media_to_mojo_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_DEVICE_MEDIA_TO_MOJO_ADAPTER_H_
 #define SERVICES_VIDEO_CAPTURE_DEVICE_MEDIA_TO_MOJO_ADAPTER_H_
 
 #include "media/capture/video/video_capture_device.h"
 #include "media/capture/video/video_capture_device_client.h"
 #include "media/capture/video_capture_types.h"
+#include "services/service_manager/public/cpp/service_context_ref.h"
 #include "services/video_capture/public/interfaces/device.mojom.h"
 
 namespace video_capture {
 
+class ReceiverMojoToMediaAdapter;
+
 // Implementation of mojom::Device backed by a given instance of
 // media::VideoCaptureDevice.
 class DeviceMediaToMojoAdapter : public mojom::Device {
  public:
-  DeviceMediaToMojoAdapter(std::unique_ptr<media::VideoCaptureDevice> device,
-                           const media::VideoCaptureJpegDecoderFactoryCB&
-                               jpeg_decoder_factory_callback);
+  DeviceMediaToMojoAdapter(
+      std::unique_ptr<service_manager::ServiceContextRef> service_ref,
+      std::unique_ptr<media::VideoCaptureDevice> device,
+      const media::VideoCaptureJpegDecoderFactoryCB&
+          jpeg_decoder_factory_callback);
   ~DeviceMediaToMojoAdapter() override;
 
-  // mojom::Device:
+  // mojom::Device implementation.
   void Start(const media::VideoCaptureParams& requested_settings,
              mojom::ReceiverPtr receiver) override;
   void OnReceiverReportingUtilization(int32_t frame_feedback_id,
                                       double utilization) override;
 
   void Stop();
 
   void OnClientConnectionErrorOrClose();
 
   // Returns the fixed maximum number of buffers passed to the constructor
   // of VideoCaptureBufferPoolImpl.
   static int max_buffer_pool_buffer_count();
 
  private:
+  const std::unique_ptr<service_manager::ServiceContextRef> service_ref_;
   const std::unique_ptr<media::VideoCaptureDevice> device_;
   media::VideoCaptureJpegDecoderFactoryCB jpeg_decoder_factory_callback_;
-  bool device_running_;
+  bool device_started_;
+  ReceiverMojoToMediaAdapter* receiver_adapter_ptr_ = nullptr;
+  base::ThreadChecker thread_checker_;
 };
 
 }  // namespace video_capture
 
 #endif  // SERVICES_VIDEO_CAPTURE_DEVICE_MEDIA_TO_MOJO_ADAPTER_H_