[Mojo Video Capture] Implement a VideoCaptureProvider using the Mojo service (part 1)

content/browser/renderer_host/media/service_video_capture_provider.h

+// Copyright 2017 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 CONTENT_BROWSER_RENDERER_HOST_MEDIA_SERVICE_VIDEO_CAPTURE_PROVIDER_H_
+#define CONTENT_BROWSER_RENDERER_HOST_MEDIA_SERVICE_VIDEO_CAPTURE_PROVIDER_H_
+
+#include "base/threading/thread_checker.h"
+#include "content/browser/renderer_host/media/video_capture_provider.h"
+#include "services/video_capture/public/interfaces/device_factory.mojom.h"
+#include "services/video_capture/public/interfaces/device_factory_provider.mojom.h"
+
+namespace service_manager {
+class Connector;
+}
+
+namespace content {
+
+// Implementation of VideoCaptureProvider that uses the "video_capture" service.
+class CONTENT_EXPORT ServiceVideoCaptureProvider : public VideoCaptureProvider {
+ public:
+  ServiceVideoCaptureProvider();
+  ~ServiceVideoCaptureProvider() override;
+
+  void Uninitialize() override;
+
+  void GetDeviceInfosAsync(
+      const base::Callback<void(
+          const std::vector<media::VideoCaptureDeviceInfo>&)>& result_callback)
+      override;
+
+  std::unique_ptr<VideoCaptureDeviceLauncher> CreateDeviceLauncher() override;
+
+ private:
+  void LazyConnectToService();
+  void OnLostConnectionToDeviceFactory();
+
+  std::unique_ptr<service_manager::Connector> connector_;
+  // We must hold on to |device_factory_provider_| because it holds the
+  // service-side binding for |device_factory_|.
+  video_capture::mojom::DeviceFactoryProviderPtr device_factory_provider_;
+  video_capture::mojom::DeviceFactoryPtr device_factory_;
+  base::ThreadChecker thread_checker_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_SERVICE_VIDEO_CAPTURE_PROVIDER_H_