[Mojo Video Capture] Introduce abstraction VideoCaptureSystem

content/browser/renderer_host/media/buildable_video_capture_device.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_BUILDABLE_VIDEO_CAPTURE_DEVICE_H_
 #define CONTENT_BROWSER_RENDERER_HOST_MEDIA_BUILDABLE_VIDEO_CAPTURE_DEVICE_H_
 
 #include "base/memory/ptr_util.h"
 #include "base/memory/ref_counted.h"
 #include "content/public/common/media_stream_request.h"
 #include "media/capture/video/video_capture_device.h"
 #include "media/capture/video_capture_types.h"
 
 namespace content {
 
 class VideoCaptureController;
 
 class CONTENT_EXPORT BuildableDeviceCallbacks {
  public:
   virtual ~BuildableDeviceCallbacks() {}
-  // Returns false if no descriptor was found.
-  virtual const media::VideoCaptureDeviceDescriptor* LookupDeviceDescriptor(
-      const std::string& id) = 0;
-  virtual void WillStartDevice(media::VideoFacingMode facing_mode) = 0;
-  virtual void DidStartDevice(VideoCaptureController* controller) = 0;
+  virtual void OnDeviceStarted(VideoCaptureController* controller) = 0;
   virtual void OnDeviceStartFailed(VideoCaptureController* controller) = 0;
   virtual void OnDeviceStartAborted() = 0;
 };
 
 // Abstraction for a video capture device that must be "built" before it can be
 // operated and must be "stopped", before it can be released. Typical operation
 // is that a newly created instance initially reports IsDeviceAlive() == false.
 // Clients call CreateAndStartDeviceAsync(), which kicks off the asynchronous
 // building of the device. The outcome of the device building is typically
 // reported to an instance of BuildableDeviceCallbacks (see above). Once the
@@ skipping 35 matching lines @@
   virtual void RequestRefreshFrame() = 0;
 
   // Methods for specific types of devices.
   virtual void SetDesktopCaptureWindowIdAsync(gfx::NativeViewId window_id,
                                               base::OnceClosure done_cb) = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_BUILDABLE_VIDEO_CAPTURE_DEVICE_H_