Integrate VDA with WebRTC.

content/renderer/media/rtc_video_decoder_factory.cc

+// Copyright (c) 2013 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.
+
+#include "content/renderer/media/rtc_video_decoder_factory.h"
+
+#include "base/location.h"
+#include "base/memory/scoped_ptr.h"
+#include "content/renderer/media/rtc_video_decoder.h"
+
+namespace content {
+
+RTCVideoDecoderFactory::RTCVideoDecoderFactory(
+    const scoped_refptr<media::GpuVideoDecoder::Factories>& gpu_factories)
+    : vda_loop_proxy_(gpu_factories->GetMessageLoop()) {
+  DVLOG(2) << "RTCVideoDecoderFactory";
+  // The decoder cannot be created in CreateVideoDecoder because VDA has to be
+  // created on |vda_loop_proxy_|, which can be the child thread. The child
+  // thread is blocked when CreateVideoDecoder runs.

[Ami GONE FROM CHROMIUM, 2013/06/18 21:54:29]

TODO that this supports only one VDA-powered <video> tag at a time, and that
IWBN to remove this restriction.

[wuchengli, 2013/06/19 13:01:13]

Done.

+  scoped_ptr<RTCVideoDecoder> decoder(new RTCVideoDecoder(gpu_factories));
+  if (decoder->InitVideoDecodeAccelerator()) {
+    decoder_.reset(decoder.release());

[Ami GONE FROM CHROMIUM, 2013/06/18 21:54:29]

FWIW instead of 
new+Init+.release/.reset
you could have a static factory method
RTCVideoDecoder::Create(const scoped_refptr<m::GVD::F>& factories)
which returned NULL on Init failure.  Your choice.

[wuchengli, 2013/06/19 13:01:13]

Sounds good. Done.

+  } else {
+    // VP8 is unsupported. Release the decoder.
+    vda_loop_proxy_->DeleteSoon(FROM_HERE, decoder.release());
+  }
+}
+
+RTCVideoDecoderFactory::~RTCVideoDecoderFactory() {
+  DVLOG(2) << "~RTCVideoDecoderFactory";
+  if (decoder_)
+    vda_loop_proxy_->DeleteSoon(FROM_HERE, decoder_.release());
+}
+
+webrtc::VideoDecoder* RTCVideoDecoderFactory::CreateVideoDecoder(
+    webrtc::VideoCodecType type) {
+  DVLOG(2) << "CreateVideoDecoder";
+  // Only VP8 is supported.
+  if (type == webrtc::kVideoCodecVP8)
+    return decoder_.release();
+  return NULL;
+}
+
+void RTCVideoDecoderFactory::DestroyVideoDecoder(
+    webrtc::VideoDecoder* decoder) {
+  DVLOG(2) << "DestroyVideoDecoder";
+  // Save back the decoder because it is the only one.
+  decoder_.reset(decoder);

[Ami GONE FROM CHROMIUM, 2013/06/18 21:54:29]

Probably want to do something like VDA::Reset() and then wait for
NotifyResetDone before reusing this decoder.

[wuchengli, 2013/06/19 13:01:13]

VDA::Release() should have been called, which does the same thing as Reset().
Decode() will queue the decode buffers until NotifyResetDone.

+}
+
+}  // namespace content