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

content/browser/renderer_host/media/video_capture_device_client.h

Index: content/browser/renderer_host/media/video_capture_device_client.h
diff --git a/content/browser/renderer_host/media/video_capture_device_client.h b/content/browser/renderer_host/media/video_capture_device_client.h
index 7da95da8e75174d4440a68122547119bed32c8d0..d194379b0401e032304cd865d8d5e3e033e6c763 100644
--- a/content/browser/renderer_host/media/video_capture_device_client.h
+++ b/content/browser/renderer_host/media/video_capture_device_client.h
@@ -24,12 +24,21 @@ class VideoCaptureController;
 // 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.
@@ -50,6 +59,9 @@ class CONTENT_EXPORT VideoCaptureDeviceClient
   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,
@@ -64,6 +76,13 @@ class CONTENT_EXPORT VideoCaptureDeviceClient
   // 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);