[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 3f41490a5974f891b8e9b128edbe58b56d889253..e358435d24d771178c82297cef114192374ab885 100644
--- a/content/browser/renderer_host/media/buildable_video_capture_device.h
+++ b/content/browser/renderer_host/media/buildable_video_capture_device.h
@@ -30,11 +30,7 @@ class CONTENT_EXPORT BuildableVideoCaptureDevice {
   class CONTENT_EXPORT Callbacks {
    public:
     virtual ~Callbacks() {}
-    // Returns nullptr 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;
   };