[Mojo Video Capture] Introduce abstraction VideoCaptureSystem

content/browser/renderer_host/media/video_capture_manager.h

 // Copyright (c) 2012 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.
 
 // VideoCaptureManager is used to open/close, start/stop, enumerate available
 // video capture devices, and manage VideoCaptureController's.
 // All functions are expected to be called from Browser::IO thread. Some helper
 // functions (*OnDeviceThread) will dispatch operations to the device thread.
 // VideoCaptureManager will open OS dependent instances of VideoCaptureDevice.
 // A device can only be opened once.
@@ skipping 16 matching lines @@
 #include "base/timer/elapsed_timer.h"
 #include "build/build_config.h"
 #include "content/browser/renderer_host/media/buildable_video_capture_device.h"
 #include "content/browser/renderer_host/media/media_stream_provider.h"
 #include "content/browser/renderer_host/media/video_capture_controller_event_handler.h"
 #include "content/common/content_export.h"
 #include "content/common/media/media_stream_options.h"
 #include "media/base/video_facing.h"
 #include "media/capture/video/video_capture_device.h"
 #include "media/capture/video/video_capture_device_factory.h"
+#include "media/capture/video/video_capture_device_info.h"
+#include "media/capture/video/video_capture_system.h"
 #include "media/capture/video_capture_types.h"
 
 #if defined(OS_ANDROID)
 #include "base/android/application_status_listener.h"
 #endif
 
 namespace content {
 class VideoCaptureController;
 class VideoCaptureControllerEventHandler;
 
 // VideoCaptureManager opens/closes and start/stops video capture devices.
 class CONTENT_EXPORT VideoCaptureManager
     : public MediaStreamProvider,
       public BuildableVideoCaptureDevice::Callbacks {
  public:
   using VideoCaptureDevice = media::VideoCaptureDevice;
 
   // Callback used to signal the completion of a controller lookup.
   using DoneCB =
       base::Callback<void(const base::WeakPtr<VideoCaptureController>&)>;
 
   VideoCaptureManager(
-      std::unique_ptr<media::VideoCaptureDeviceFactory> factory,
+      std::unique_ptr<media::VideoCaptureSystem> capture_system,
       scoped_refptr<base::SingleThreadTaskRunner> device_task_runner);
 
   // AddVideoCaptureObserver() can be called only before any devices are opened.
   // RemoveAllVideoCaptureObservers() can be called only after all devices
   // are closed.
   // They can be called more than once and it's ok to not call at all if the
   // client is not interested in receiving media::VideoCaptureObserver callacks.
   // This methods can be called on whatever thread. The callbacks of
   // media::VideoCaptureObserver arrive on browser IO thread.
   void AddVideoCaptureObserver(media::VideoCaptureObserver* observer);
@@ skipping 86 matching lines @@
                              const std::string& device_id,
                              media::VideoCaptureFormats* supported_formats);
 
   // Sets the platform-dependent window ID for the desktop capture notification
   // UI for the given session.
   void SetDesktopCaptureWindowId(media::VideoCaptureSessionId session_id,
                                  gfx::NativeViewId window_id);
 
   // Gets a weak reference to the device factory, used for tests.
   media::VideoCaptureDeviceFactory* video_capture_device_factory() const {
-    return video_capture_device_factory_.get();
+    return video_capture_system_->video_capture_device_factory();
   }
 
 #if defined(OS_WIN)
   void set_device_task_runner(
       const scoped_refptr<base::SingleThreadTaskRunner>& device_task_runner) {
     device_task_runner_ = device_task_runner;
   }
 #endif
 
   // Returns the SingleThreadTaskRunner where devices are enumerated on and
@@ skipping 13 matching lines @@
 
 #if defined(OS_ANDROID)
   // Some devices had troubles when stopped and restarted quickly, so the device
   // is only stopped when Chrome is sent to background and not when, e.g., a tab
   // is hidden, see http://crbug.com/582295.
   void OnApplicationStateChange(base::android::ApplicationState state);
 #endif
 
   using EnumerationCallback =
       base::Callback<void(const media::VideoCaptureDeviceDescriptors&)>;
+  // Asynchronously obtains descriptors for the available devices.
+  // As a side-effect, updates |devices_info_cache_|.
   void EnumerateDevices(const EnumerationCallback& client_callback);
 
   // Implementation of BuildableVideoCaptureDevice::Callbacks:
-  const media::VideoCaptureDeviceDescriptor* LookupDeviceDescriptor(
-      const std::string& id) override;
-  void WillStartDevice(media::VideoFacingMode facing_mode) override;
-  void DidStartDevice(VideoCaptureController* controller) override;
+  void OnDeviceStarted(VideoCaptureController* controller) override;
   void OnDeviceStartFailed(VideoCaptureController* controller) override;
   void OnDeviceStartAborted() override;
 
   // Retrieves camera calibration information for a particular device. Returns
   // nullopt_t if the |device_id| is not found or camera calibration information
   // is not available for the device.  Camera calibration is cached during
   // device(s) enumeration.
   base::Optional<CameraCalibration> GetCameraCalibration(
       const std::string& device_id);
 
  private:
   class CaptureDeviceStartRequest;
-  struct DeviceInfo;
 
   using SessionMap = std::map<media::VideoCaptureSessionId, MediaStreamDevice>;
-  using DeviceInfos = std::vector<DeviceInfo>;
   using DeviceStartQueue = std::list<CaptureDeviceStartRequest>;
   using VideoCaptureDeviceDescriptor = media::VideoCaptureDeviceDescriptor;
   using VideoCaptureDeviceDescriptors = media::VideoCaptureDeviceDescriptors;
 
   ~VideoCaptureManager() override;
 
+  void OnDeviceInfosReceived(
+      base::ElapsedTimer* timer,
+      const EnumerationCallback& client_callback,
+      const std::vector<media::VideoCaptureDeviceInfo>& device_infos);
+
   // Helpers to report an event to our Listener.
   void OnOpened(MediaStreamType type,
                 media::VideoCaptureSessionId capture_session_id);
   void OnClosed(MediaStreamType type,
                 media::VideoCaptureSessionId capture_session_id);
-  void OnDevicesInfoEnumerated(base::ElapsedTimer* timer,
-                               const EnumerationCallback& client_callback,
-                               const DeviceInfos& new_devices_info_cache);
-
-  // Consolidates the cached devices list with the list of currently connected
-  // devices in the system |names_snapshot|. Retrieves the supported formats of
-  // the new devices and sends the new cache to OnDevicesInfoEnumerated().
-  void ConsolidateDevicesInfoOnDeviceThread(
-      base::Callback<void(const DeviceInfos&)> on_devices_enumerated_callback,
-      const DeviceInfos& old_device_info_cache,
-      std::unique_ptr<VideoCaptureDeviceDescriptors> descriptors_snapshot);
 
   // Checks to see if |controller| has no clients left. If so, remove it from
   // the list of controllers, and delete it asynchronously. |controller| may be
   // freed by this function.
   void DestroyControllerIfNoClients(VideoCaptureController* controller);
 
   // Finds a VideoCaptureController in different ways: by |session_id|, by its
   // |device_id| and |type| (if it is already opened), by its |controller| or by
   // its |serial_id|. In all cases, if not found, nullptr is returned.
   VideoCaptureController* LookupControllerBySessionId(int session_id);
   VideoCaptureController* LookupControllerByMediaTypeAndDeviceId(
       MediaStreamType type,
       const std::string& device_id) const;
   bool IsControllerPointerValid(const VideoCaptureController* controller) const;
   scoped_refptr<VideoCaptureController> GetControllerSharedRef(
       VideoCaptureController* controller) const;
 
   // Finds the device info by |id| in |devices_info_cache_|, or nullptr.
-  DeviceInfo* GetDeviceInfoById(const std::string& id);
+  media::VideoCaptureDeviceInfo* GetDeviceInfoById(const std::string& id);
 
   // Finds a VideoCaptureController for the indicated |capture_session_id|,
   // creating a fresh one if necessary. Returns nullptr if said
   // |capture_session_id| is invalid.
   VideoCaptureController* GetOrCreateController(
       media::VideoCaptureSessionId capture_session_id,
       const media::VideoCaptureParams& params);
 
   // Starting a capture device can take 1-2 seconds.
   // To avoid multiple unnecessary start/stop commands to the OS, each start
@@ skipping 37 matching lines @@
   std::vector<scoped_refptr<VideoCaptureController>> controllers_;
 
   DeviceStartQueue device_start_request_queue_;
 
   // Queue to keep photo-associated requests waiting for a device to initialize,
   // bundles a session id integer and an associated photo-related request.
   std::list<std::pair<int, base::Closure>> photo_request_queue_;
 
   // Device creation factory injected on construction from MediaStreamManager or
   // from the test harness.
-  std::unique_ptr<media::VideoCaptureDeviceFactory>
-      video_capture_device_factory_;
+  std::unique_ptr<media::VideoCaptureSystem> video_capture_system_;
 
   base::ObserverList<media::VideoCaptureObserver> capture_observers_;
 
-  // Local cache of the enumerated video capture devices' names and capture
-  // supported formats. A snapshot of the current devices and their capabilities
-  // is composed in VideoCaptureDeviceFactory::EnumerateDeviceNames() and
-  // ConsolidateDevicesInfoOnDeviceThread(), and this snapshot is used to update
-  // this list in OnDevicesInfoEnumerated(). GetDeviceSupportedFormats() will
+  // Local cache of the enumerated DeviceInfos. GetDeviceSupportedFormats() will
   // use this list if the device is not started, otherwise it will retrieve the
   // active device capture format from the VideoCaptureController associated.
-  DeviceInfos devices_info_cache_;
+  std::vector<media::VideoCaptureDeviceInfo> devices_info_cache_;
 
   // Map used by DesktopCapture.
   std::map<media::VideoCaptureSessionId, gfx::NativeViewId>
       notification_window_ids_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoCaptureManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_MANAGER_H_