Make VideoCaptureController single-threaded and not ref counted.

media/video/capture/video_capture_device_dummy.cc

-// Copyright (c) 2011 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 "media/video/capture/video_capture_device_dummy.h"
-
-namespace media {
-
-VideoCaptureDevice* VideoCaptureDevice::Create(const Name& device_name) {
-  return NULL;
-}
-
-void VideoCaptureDevice::GetDeviceNames(Names* device_names) {}
-
-VideoCaptureDeviceDummy::VideoCaptureDeviceDummy() {}
-
-VideoCaptureDeviceDummy::~VideoCaptureDeviceDummy() {}
-
-void VideoCaptureDeviceDummy::Allocate(
-    const VideoCaptureCapability& capture_format,
-    VideoCaptureDevice::EventHandler* observer) {
-}
-
-void VideoCaptureDeviceDummy::Start() {}
-
-void VideoCaptureDeviceDummy::Stop() {}
-
-void VideoCaptureDeviceDummy::DeAllocate() {}
-
-}  // namespace media