[Mojo Video Capture] Simplify media::VideoCaptureDevice::Client:Buffer to a struct

media/capture/video/video_capture_buffer_tracker.h

 // Copyright 2016 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 MEDIA_CAPTURE_VIDEO_VIDEO_CAPTURE_BUFFER_TRACKER_H_
 #define MEDIA_CAPTURE_VIDEO_VIDEO_CAPTURE_BUFFER_TRACKER_H_
 
 #include <memory>
 
 #include "base/synchronization/lock.h"
@@ skipping 32 matching lines @@
   void set_storage_type(media::VideoPixelStorage storage_type) {
     storage_type_ = storage_type;
   }
   bool held_by_producer() const { return held_by_producer_; }
   void set_held_by_producer(bool value) { held_by_producer_ = value; }
   int consumer_hold_count() const { return consumer_hold_count_; }
   void set_consumer_hold_count(int value) { consumer_hold_count_ = value; }
   void set_frame_feedback_id(int value) { frame_feedback_id_ = value; }
   int frame_feedback_id() { return frame_feedback_id_; }
 
-  // Returns a scoped handle to the underlying storage.
-  virtual std::unique_ptr<VideoCaptureBufferHandle> GetBufferHandle() = 0;
-
+  virtual std::unique_ptr<VideoCaptureBufferHandle> GetMemoryMappedAccess() = 0;
   virtual mojo::ScopedSharedBufferHandle GetHandleForTransit() = 0;
 
  private:
   // |dimensions_| may change as a VideoCaptureBufferTracker is re-used, but
   // |max_pixel_count_|, |pixel_format_|, and |storage_type_| are set once for
   // the lifetime of a VideoCaptureBufferTracker.
   gfx::Size dimensions_;
   size_t max_pixel_count_;
   media::VideoPixelFormat pixel_format_;
   media::VideoPixelStorage storage_type_;
 
   // Indicates whether this VideoCaptureBufferTracker is currently referenced by
   // the producer.
   bool held_by_producer_;
 
   // Number of consumer processes which hold this VideoCaptureBufferTracker.
   int consumer_hold_count_;
 
   int frame_feedback_id_;
 };
 
 }  // namespace content
 
 #endif  // MEDIA_CAPTURE_VIDEO_VIDEO_CAPTURE_BUFFER_TRACKER_H_