Extract VideoCaptureDeviceFactory out of VideoCaptureDevice and use for File and FakeVCD.

media/video/capture/video_capture_device_factory.h

+// Copyright 2014 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 MEDIA_VIDEO_CAPTURE_VIDEO_CAPTURE_DEVICE_FACTORY_H_
+#define MEDIA_VIDEO_CAPTURE_VIDEO_CAPTURE_DEVICE_FACTORY_H_
+
+#include "media/video/capture/video_capture_device.h"
+
+namespace media {
+
+// VideoCaptureDeviceFactory is the abstract base class for creation of video
+// capture devices in the different platforms. Derived classes are created and
+// owned by VideoCaptureManager in IO Thread.

[perkj_chrome, 2014/04/15 09:34:01]

is That really true? I thought the VideoCaptureManager called these methods on a
special thread owned by MediaStreamManager since it may take a long time to
enumerate.

[mcasas, 2014/04/15 13:47:09]

MediaStreamManager lives between UI thread and IO thread. 
VideoCaptureManager lives between IO thread and Device thread.
The special thread for enumeration is the Device thread, for all
platforms except for Mac QTKit (AVFoundation is migrating).

+class MEDIA_EXPORT VideoCaptureDeviceFactory {
+ public:
+  VideoCaptureDeviceFactory() {};
+  virtual ~VideoCaptureDeviceFactory() {};
+
+  // Creates a VideoCaptureDevice object. Returns NULL if something goes wrong.
+  // TODO(mcasas): Return a scoped_ptr to make ownership explicit.
+  virtual VideoCaptureDevice* Create(

[perkj_chrome, 2014/04/15 09:34:01]

Add areal implementation of this interface as well. It can call the existing
static methods.

[mcasas, 2014/04/15 13:47:09]

Done.

+      const VideoCaptureDevice::Name& device_name) = 0;
+
+  // Gets the names of all video capture devices connected to this computer.
+  virtual void GetDeviceNames(VideoCaptureDevice::Names* device_names) = 0;
+
+  // Gets the supported formats of a particular device attached to the system.
+  // This method should be called before allocating or starting a device. In
+  // case format enumeration is not supported, or there was a problem, the
+  // formats array will be empty.
+  virtual void GetDeviceSupportedFormats(
+      const VideoCaptureDevice::Name& device,
+      VideoCaptureFormats* supported_formats) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(VideoCaptureDeviceFactory);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_VIDEO_CAPTURE_VIDEO_CAPTURE_DEVICE_FACTORY_H_