Extract nested and private classes from VideoCaptureBufferPool

content/browser/renderer_host/media/video_capture_buffer_tracker_factory.h

+// 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.
+
+#ifndef CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_BUFFER_TRACKER_FACTORY_H_
+#define CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_BUFFER_TRACKER_FACTORY_H_
+
+#include <memory>
+
+#include "content/browser/renderer_host/media/video_capture_buffer_tracker.h"
+
+namespace content {
+
+class VideoCaptureBufferTrackerFactory {
+ public:
+  static std::unique_ptr<VideoCaptureBufferTracker> CreateTracker(
+      media::VideoPixelStorage storage);

[mcasas, 2016/09/20 00:51:08]

If there is just this method you can consider pegging it to 
video_capture_buffer_tracker.h, right? (It's quite verbose
to have to add 2 files).

[chfremer, 2016/09/20 18:43:10]

I agree, and it actually used to be part of the Tracker interface class.

The reason I would like to separate it out here already is that in the next CL 
this static method is going to change into a pure virtual one, making 
this an actual interface. This is needed to break the dependency of
VideoCaptureBufferPool
on the concrete factory. The Video Capture Mojo service is then going to 
provide a different implementation than the existing one used by
VideoCaptureManager.

+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_BUFFER_TRACKER_FACTORY_H_