[Mojo Video Capture] Introduce abstraction VideoCaptureSystem

content/browser/renderer_host/media/buildable_video_capture_device.h

Index: content/browser/renderer_host/media/buildable_video_capture_device.h
diff --git a/content/browser/renderer_host/media/buildable_video_capture_device.h b/content/browser/renderer_host/media/buildable_video_capture_device.h
index 11f2d5668cc34e2461238f13ef10c1655a3421a4..59118aa2e4b1342c4c262a540dbc9b65b9733569 100644
--- a/content/browser/renderer_host/media/buildable_video_capture_device.h
+++ b/content/browser/renderer_host/media/buildable_video_capture_device.h
@@ -18,11 +18,7 @@ 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;
 };