VideoCapture: add support for GpuMemoryBuffer allocation and lifetime mgmt in VideoCaptureBufferPool

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 "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "content/common/content_export.h"
 #include "media/video/capture/video_capture_device.h"
 
 namespace content {
 class VideoCaptureBufferPool;
 class VideoCaptureController;
 
 // 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.
 //
 // 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.
+//
+// It has an internal ref counted TextureWrapperDelegate class used to wrap
+// incoming GpuMemoryBuffers into Texture backed Videoframes. This class creates
+// and manages the necessary interactions with the GPU process, notably an
+// offscreen Context to avoid janking the UI thread. This delegate is also
+// needed since the frame producer owns VideoCaptureDeviceClient, but this needs
+// to launch PostTask()s to the delegate.
 class CONTENT_EXPORT VideoCaptureDeviceClient
     : public media::VideoCaptureDevice::Client {
  public:
   VideoCaptureDeviceClient(
       const base::WeakPtr<VideoCaptureController>& controller,
-      const scoped_refptr<VideoCaptureBufferPool>& buffer_pool);
+      const scoped_refptr<VideoCaptureBufferPool>& buffer_pool,
+      const scoped_refptr<base::SingleThreadTaskRunner>& capture_task_runner,
+      const media::VideoCaptureFormat& capture_format);
   ~VideoCaptureDeviceClient() override;
 
   // VideoCaptureDevice::Client implementation.
   void OnIncomingCapturedData(const uint8* data,
                               int length,
                               const media::VideoCaptureFormat& frame_format,
                               int rotation,
                               const base::TimeTicks& timestamp) override;
   void OnIncomingCapturedYuvData(const uint8* y_data,
                                  const uint8* u_data,
                                  const uint8* v_data,
                                  size_t y_stride,
                                  size_t u_stride,
                                  size_t v_stride,
                                  const media::VideoCaptureFormat& frame_format,
                                  int clockwise_rotation,
                                  const base::TimeTicks& timestamp) override;
   scoped_refptr<Buffer> ReserveOutputBuffer(
       media::VideoPixelFormat format,
       const gfx::Size& dimensions) override;
+  void OnIncomingCapturedBuffer(const scoped_refptr<Buffer>& buffer,
+                                const media::VideoCaptureFormat& frame_format,
+                                const base::TimeTicks& timestamp) override;
   void OnIncomingCapturedVideoFrame(
       const scoped_refptr<Buffer>& buffer,
       const scoped_refptr<media::VideoFrame>& frame,
       const base::TimeTicks& timestamp) override;
   void OnError(const std::string& reason) override;
   void OnLog(const std::string& message) override;
 
  private:
   // The controller to which we post events.
   const base::WeakPtr<VideoCaptureController> controller_;
 
   // The pool of shared-memory buffers used for capturing.
   const scoped_refptr<VideoCaptureBufferPool> buffer_pool_;
 
+  // Internal delegate for GpuMemoryBuffer-into-VideoFrame wrapping. Created if
+  // |capture_format| on constructor specifies PIXEL_FORMAT_GPUMEMORYBUFFER.
+  class TextureWrapperDelegate;
+  scoped_refptr<TextureWrapperDelegate> wrapper_delegate_;
+  // Reference to Capture Thread task runner, where |wrapper_delegate_| lives.
+  const scoped_refptr<base::SingleThreadTaskRunner> capture_task_runner_;
+
   media::VideoPixelFormat last_captured_pixel_format_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoCaptureDeviceClient);
 };
 
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_DEVICE_CLIENT_H_