Pass GpuMemoryBuffer backed VideoFrame from browser to renderer processes

This is a CL for Video Capture using GpuMemoryBuffers plan[0]. The plans for future CLs can be seen on [1].

[0] https://docs.google.com/document/d/1lobWf168_Kq05TLNLX81gRQwY5oe4k2t3oP-XTBEpIo/edit#heading=h.lflt7hoq3oui
[1] https://docs.google.com/document/d/1lobWf168_Kq05TLNLX81gRQwY5oe4k2t3oP-XTBEpIo/edit#heading=h.exy0h9917c1d

- Changed VideoCaptureBufferPool::ShareToProcess() method to handle sharing both SharedMemory and GpuMemoryBuffer backed video frames.
- Added VideoCaptureBufferPool::GpuMemoryBufferTracker::ShareToProcess() for sharing GMB backed buffers.
- Added dimensions() method to media::VideoCaptureDevice::Client::Buffer and VideoCaptureBufferPool::BufferHandle interfaces as required by GMB mapping. Also, renamed size() to mapped_size() to avoid confusion.
- Added OnGpuMemoryBufferCreated() calls between Browser and Renderer to notify the creation of GMB backed buffers and pass handles.
- Added VideoCaptureImpl::ClientGpuMemoryBuffer on Renderer side to create&map new GMB client buffers.

Also, buffer reuse and destruction is handled behind VideoCaptureDeviceClient::AutoReleaseBuffer like listed below:

Buffer Creation
*Browser
VideoCaptureController::DoIncomingCapturedVideoFrameOnIOThread
- ShareToProcess(Renderer)
VideoCaptureHost::OnBufferCreated
*Renderer
VideoCaptureMessageFilter::OnBufferCreated
VideoCaptureImpl::OnBufferCreated
- Adds to client_buffers_

Buffer Reuse
*Renderer
VideoCaptureImpl::OnClientBufferFinished
*Browser
VideoCaptureHost::OnRendererFinishedWithBuffer
VideoCaptureController::ReturnBuffer
VideoCaptureBufferPool::RelinquishConsumerHold
~AutoReleaseBuffer
VideoCaptureBufferPool::RelinquishProducerReservation

BUG=440843, 503835
TEST=
- Without the kUseGpuMemoryBuffersForCapture flag, AppRTC loopback runs as before.
- With the flag, AppRTC loopback crashes in VideoCaptureHost::OnBufferReady as expected.

Review URL: https://codereview.chromium.org/1267883002

Cr-Commit-Position: refs/heads/master@{#346414}

1 files changed, 2 insertions, 1 deletions

diff --git a/content/browser/renderer_host/media/video_capture_device_client.cc b/content/browser/renderer_host/media/video_capture_device_client.cc
index ade0d74..2adf8d1 100644
--- a/content/browser/renderer_host/media/video_capture_device_client.cc
+++ b/content/browser/renderer_host/media/video_capture_device_client.cc
@@ -121,7 +121,8 @@ class AutoReleaseBuffer : public media::VideoCaptureDevice::Client::Buffer {
     DCHECK(pool_.get());
   }
   int id() const override { return id_; }
-  size_t size() const override { return buffer_handle_->size(); }
+  gfx::Size dimensions() const override { return buffer_handle_->dimensions(); }
+  size_t mapped_size() const override { return buffer_handle_->mapped_size(); }
   void* data(int plane) override { return buffer_handle_->data(plane); }
   ClientBuffer AsClientBuffer(int plane) override {
     return buffer_handle_->AsClientBuffer(plane);