[Mojo Video Capture] Decouple VCController from VCBufferPool and VCDeviceClient

media/capture/video/video_capture_device.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.
 //
 // VideoCaptureDevice is the abstract base class for realizing video capture
 // device support in Chromium. It provides the interface for OS dependent
 // implementations.
 // The class is created and functions are invoked on a thread owned by
 // VideoCaptureManager. Capturing is done on other threads, depending on the OS
 // specific implementation.
@@ skipping 23 matching lines @@
 #include "media/capture/video_capture_types.h"
 #include "mojo/public/cpp/bindings/array.h"
 #include "ui/gfx/gpu_memory_buffer.h"
 
 namespace tracked_objects {
 class Location;
 }  // namespace tracked_objects
 
 namespace media {
 
+class CAPTURE_EXPORT FrameBufferHost {

[mcasas, 2016/12/06 20:02:24]

In Chromium, Hosts are usually sitting at one end
of an IPC/mojo channel. To avoid confusion, we 
could consider calling this class e.g. FrameBufferPool?

[chfremer, 2016/12/06 21:07:41]

Done.

+ public:
+  virtual ~FrameBufferHost() {}
+
+  virtual void SetBufferHold(int buffer_id) = 0;
+  virtual void ReleaseBufferHold(int buffer_id) = 0;
+  virtual mojo::ScopedSharedBufferHandle GetHandleForTransit(int buffer_id) = 0;
+};

[mcasas, 2016/12/06 20:02:24]

Move it to a file on its own plz.

[chfremer, 2016/12/06 21:07:41]

Please allow me to defer this as cleanup task by adding it to the design doc.
Actually, this interface will be eliminated anyway in CL1.9.10.

+
 class CAPTURE_EXPORT VideoFrameConsumerFeedbackObserver {

[mcasas, 2016/12/06 20:02:24]

We should move this fella to a file on its own too.

And, incidentally, we should move these interface
definitions to media/capture ISO being buried
in media/capture/video. This can be done after
this CL.

[chfremer, 2016/12/06 21:07:41]

Agreed.
Please allow me to defer this as cleanup task by adding it to the design doc.

  public:
   virtual ~VideoFrameConsumerFeedbackObserver() {}
 
   // During processing of a video frame, consumers may report back their
   // utilization level to the source device. The device may use this information
   // to adjust the rate of data it pushes out. Values are interpreted as
   // follows:
   // Less than 0.0 is meaningless and should be ignored.  1.0 indicates a
   // maximum sustainable utilization.  Greater than 1.0 indicates the consumer
   // is likely to stall or drop frames if the data volume is not reduced.
@@ skipping 86 matching lines @@
     // Captured new video data, held in |frame| or |buffer|, respectively for
     // OnIncomingCapturedVideoFrame() and  OnIncomingCapturedBuffer().
     //
     // In both cases, as the frame is backed by a reservation returned by
     // ReserveOutputBuffer(), delivery is guaranteed and will require no
     // additional copies in the browser process.
     // See OnIncomingCapturedData for details of |reference_time| and
     // |timestamp|.
     // TODO(chfremer): Consider removing one of the two in order to simplify the
     // interface.
-    virtual void OnIncomingCapturedBuffer(
-        std::unique_ptr<Buffer> buffer,
-        const VideoCaptureFormat& frame_format,
-        base::TimeTicks reference_time,
-        base::TimeDelta timestamp) = 0;
+    virtual void OnIncomingCapturedBuffer(std::unique_ptr<Buffer> buffer,
+                                          const VideoCaptureFormat& format,
+                                          base::TimeTicks reference_time,
+                                          base::TimeDelta timestamp) = 0;
     virtual void OnIncomingCapturedVideoFrame(
         std::unique_ptr<Buffer> buffer,
         scoped_refptr<VideoFrame> frame) = 0;
 
     // Attempts to reserve the same Buffer provided in the last call to one of
     // the OnIncomingCapturedXXX() methods. This will fail if the content of the
     // Buffer has not been preserved, or if the |dimensions|, |format|, or
     // |storage| disagree with how it was reserved via ReserveOutputBuffer().
     // When this operation fails, nullptr will be returned.
     virtual std::unique_ptr<Buffer> ResurrectLastOutputBuffer(
@@ skipping 101 matching lines @@
 
  private:
   // Gets the power line frequency from the current system time zone if this is
   // defined, otherwise returns 0.
   PowerLineFrequency GetPowerLineFrequencyForLocation() const;
 };
 
 }  // namespace media
 
 #endif  // MEDIA_CAPTURE_VIDEO_VIDEO_CAPTURE_DEVICE_H_