Revert of [Mojo Video Capture] Simplify media::VideoCaptureDevice::Client:Buffer to a struct

services/video_capture/buffer_tracker_factory_impl.cc

Index: services/video_capture/buffer_tracker_factory_impl.cc
diff --git a/services/video_capture/buffer_tracker_factory_impl.cc b/services/video_capture/buffer_tracker_factory_impl.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2b502ab9dd948434cb75fcefc48b95ab43ca3388
--- /dev/null
+++ b/services/video_capture/buffer_tracker_factory_impl.cc
@@ -0,0 +1,22 @@
+// 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 "services/video_capture/buffer_tracker_factory_impl.h"
+
+#include "base/memory/ptr_util.h"
+#include "services/video_capture/mojo_shared_memory_buffer_tracker.h"
+
+namespace video_capture {
+
+std::unique_ptr<media::VideoCaptureBufferTracker>
+BufferTrackerFactoryImpl::CreateTracker(media::VideoPixelStorage storage) {
+  switch (storage) {
+    case media::PIXEL_STORAGE_CPU:
+      return base::MakeUnique<MojoSharedMemoryBufferTracker>();
+  }
+  NOTREACHED();
+  return std::unique_ptr<media::VideoCaptureBufferTracker>();
+}
+
+}  // namespace video_capture