[Mojo Video Capture] Decouple VCController from VCBufferPool and VCDeviceClient

content/browser/renderer_host/media/video_frame_receiver_on_io_thread.cc

+// Copyright 2016 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/browser/renderer_host/media/video_frame_receiver_on_io_thread.h"
+
+#include "content/public/browser/browser_thread.h"
+
+namespace content {
+
+VideoFrameReceiverOnIOThread::VideoFrameReceiverOnIOThread(
+    const base::WeakPtr<VideoFrameReceiver>& receiver)
+    : receiver_(receiver) {}
+
+VideoFrameReceiverOnIOThread::~VideoFrameReceiverOnIOThread() = default;
+
+void VideoFrameReceiverOnIOThread::OnIncomingCapturedVideoFrame(
+    std::unique_ptr<media::VideoCaptureDevice::Client::Buffer> buffer,
+    scoped_refptr<media::VideoFrame> frame) {
+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO, FROM_HERE,

[mcasas, 2016/12/06 20:02:24]

Instead of using content::BrowserThread::IO here, 
consider:
- not adding the suffix OnIOThread, but perhaps 
 just OnTaskRunner,
- adding a member,
   const scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
- which is initialized on ctor with
 BrowserThread::GetTaskRunnerForThread(BrowserThread::IO);

Note that you don't need content:: in these files.

[chfremer, 2016/12/06 21:07:41]

Good suggestion. Agreed. The ...OnTaskRunner seems like a good general pattern
and is much more flexible than the hard-coded hop to the Browser thread. Added
this to the cleanup tasks in the design doc (trying to avoid the file rename at
this point).

[mcasas, 2016/12/14 17:50:49]

Could you please add a TODO() ?

[chfremer, 2016/12/14 18:04:47]

Done.

+      base::Bind(&VideoFrameReceiver::OnIncomingCapturedVideoFrame, receiver_,
+                 base::Passed(&buffer), frame));
+}
+
+void VideoFrameReceiverOnIOThread::OnError() {
+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO, FROM_HERE,
+      base::Bind(&VideoFrameReceiver::OnError, receiver_));
+}
+
+void VideoFrameReceiverOnIOThread::OnLog(const std::string& message) {
+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO, FROM_HERE,
+      base::Bind(&VideoFrameReceiver::OnLog, receiver_, message));
+}
+
+void VideoFrameReceiverOnIOThread::OnBufferDestroyed(int buffer_id_to_drop) {
+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO, FROM_HERE,
+      base::Bind(&VideoFrameReceiver::OnBufferDestroyed, receiver_,
+                 buffer_id_to_drop));
+}
+
+}  // namespace content