Break tight coupling of VideoCaptureDeviceClient to renderer_host

content/browser/renderer_host/media/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 CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_DEVICE_CLIENT_H_
 #define CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_DEVICE_CLIENT_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "content/common/content_export.h"
 #include "media/capture/video/video_capture_device.h"
 
 namespace content {
 class VideoCaptureBufferPool;
-class VideoCaptureController;
-class VideoCaptureGpuJpegDecoder;
+class VideoFrameReceiver;
+class VideoCaptureJpegDecoder;
 
-// Receives events from the VideoCaptureDevice and posts them to a |controller_|
-// on the IO thread. An instance of this class may safely outlive its target
-// VideoCaptureController. This is a shallow class meant to convert incoming
-// frames and holds no significant state.
+using VideoCaptureJpegDecoderFactoryCB =
+    base::Callback<std::unique_ptr<VideoCaptureJpegDecoder>()>;
+
+// Implementation of media::VideoCaptureDevice::Client that uses a buffer pool
+// to provide buffers and converts incoming data to the I420 format for
+// consumption by a given VideoFrameReceiver.
 //
 // Methods of this class may be called from any thread, and in practice will
 // often be called on some auxiliary thread depending on the platform and the
 // device type; including, for example, the DirectShow thread on Windows, the
 // v4l2_thread on Linux, and the UI thread for tab capture.
+// The owner is responsible for making sure that the instance outlives these
+// calls.
 //
 // It has an internal ref counted TextureWrapHelper class used to wrap incoming
 // GpuMemoryBuffers into Texture backed VideoFrames. This class creates and
 // manages the necessary entities to interact with the GPU process, notably an
 // offscreen Context to avoid janking the UI thread.
 class CONTENT_EXPORT VideoCaptureDeviceClient
     : public media::VideoCaptureDevice::Client,
       public base::SupportsWeakPtr<VideoCaptureDeviceClient> {
  public:
   VideoCaptureDeviceClient(
-      const base::WeakPtr<VideoCaptureController>& controller,
-      const scoped_refptr<VideoCaptureBufferPool>& buffer_pool);
+      std::unique_ptr<VideoFrameReceiver> receiver,
+      const scoped_refptr<VideoCaptureBufferPool>& buffer_pool,
+      const VideoCaptureJpegDecoderFactoryCB& jpeg_decoder_factory);
   ~VideoCaptureDeviceClient() override;
 
   // VideoCaptureDevice::Client implementation.
   void OnIncomingCapturedData(const uint8_t* data,
                               int length,
                               const media::VideoCaptureFormat& frame_format,
                               int rotation,
                               base::TimeTicks reference_time,
                               base::TimeDelta timestamp) override;
   std::unique_ptr<Buffer> ReserveOutputBuffer(
@@ skipping 29 matching lines @@
   // GpuMemoryBuffers in R_8 format representing I420 planes are reserved. The
   // output buffers stay reserved and mapped for use until the Buffer objects
   // are destroyed or returned.
   std::unique_ptr<Buffer> ReserveI420OutputBuffer(
       const gfx::Size& dimensions,
       media::VideoPixelStorage storage,
       uint8_t** y_plane_data,
       uint8_t** u_plane_data,
       uint8_t** v_plane_data);
 
-  // The controller to which we post events.
-  const base::WeakPtr<VideoCaptureController> controller_;
+  // The receiver to which we post events.
+  const std::unique_ptr<VideoFrameReceiver> receiver_;
 
-  // Hardware JPEG decoder.
-  std::unique_ptr<VideoCaptureGpuJpegDecoder> external_jpeg_decoder_;
+  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_;
 
   // 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()
 
   // Indication to the Client to copy-transform the incoming data into
   // GpuMemoryBuffers.
   const bool use_gpu_memory_buffers_;
 
   media::VideoPixelFormat last_captured_pixel_format_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoCaptureDeviceClient);
 };
 
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_DEVICE_CLIENT_H_