[Mojo Video Capture] Add test coverage for accelerated jpeg decoding

media/capture/video/video_capture_device_client.h

 // Copyright 2015 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_DEVICE_CLIENT_H_
 #define MEDIA_CAPTURE_VIDEO_VIDEO_CAPTURE_DEVICE_CLIENT_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 67 matching lines @@
                                    media::VideoPixelFormat format,
                                    media::VideoPixelStorage storage,
                                    int new_frame_feedback_id) override;
   void OnError(const tracked_objects::Location& from_here,
                const std::string& reason) override;
   void OnLog(const std::string& message) override;
   void OnStarted() override;
   double GetBufferPoolUtilization() const override;
 
  private:
+  void OnUsingExternalJpegDecoder();
+
   void InitializeI420PlanePointers(const gfx::Size& dimensions,
                                    uint8_t* const data,
                                    uint8_t** y_plane_data,
                                    uint8_t** u_plane_data,
                                    uint8_t** v_plane_data);
 
   // A branch of OnIncomingCapturedData for Y16 frame_format.pixel_format.
   void OnIncomingCapturedY16Data(const uint8_t* data,
                                  int length,
                                  const VideoCaptureFormat& frame_format,
                                  base::TimeTicks reference_time,
                                  base::TimeDelta timestamp,
                                  int frame_feedback_id);
 
   // The receiver to which we post events.
   const std::unique_ptr<VideoFrameReceiver> receiver_;
   std::vector<int> buffer_ids_known_by_receiver_;
 
   const VideoCaptureJpegDecoderFactoryCB jpeg_decoder_factory_callback_;
   std::unique_ptr<VideoCaptureJpegDecoder> external_jpeg_decoder_;
 
   // Whether |external_jpeg_decoder_| has been initialized.
   bool external_jpeg_decoder_initialized_;
+  bool using_external_jpeg_decoder_;

[mcasas, 2017/03/08 01:33:17]

What about removing OnUsingExternalJpegDecoder()
and |using_external_jpeg_decoder_|, instead having
a base::CallbackOnce, you bind it using BindOnce(), 
in the ctor and with base::Unretained(receiver_) and 
VideoFrameReceiver::OnStartedUsingGpuDecode().
Test before Run()ing it as you'd do with a unique_ptr.

[chfremer, 2017/03/08 18:58:08]

Done.

 
   // The pool of shared-memory buffers used for capturing.
   const scoped_refptr<VideoCaptureBufferPool> buffer_pool_;
 
 #if DCHECK_IS_ON()
   // Counter used to track the number of times consecutive capture buffers are
   // dropped.
   int dropped_frame_counter_ = 0;
 
   static const int kMaxDroppedFrames = 150;
 #endif  // DCHECK_IS_ON()
 
   media::VideoPixelFormat last_captured_pixel_format_;
 
   // Thread collision warner to ensure that producer-facing API is not called
   // concurrently. Producers are allowed to call from multiple threads, but not
   // concurrently.
   DFAKE_MUTEX(call_from_producer_);
 
   DISALLOW_COPY_AND_ASSIGN(VideoCaptureDeviceClient);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_CAPTURE_VIDEO_VIDEO_CAPTURE_DEVICE_CLIENT_H_