Implement GpuArcVideoService for arc video accelerator

components/arc/video/arc_video_service.h

+// Copyright 2015 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 COMPONENTS_ARC_ARC_VIDEO_SERVICE_H
+#define COMPONENTS_ARC_ARC_VIDEO_SERVICE_H
+
+namespace arc {
+
+// ArcVideoService is an abstract class providing video decoding/encoding
+// acceleration service.

[Pawel Osciak, 2015/12/23 06:24:01]

We should probably mention that the purpose of this class is to create a channel
into the GPU process only, which then handles video decoding/encoding, without
going through ArcVideoService anymore?

[kcwu, 2015/12/23 09:09:43]

Done.

+class ArcVideoService {
+ public:
+  virtual ~ArcVideoService();
+
+  // Initializes and registers itself to ArcBridgeService.
+  virtual void Initialize() = 0;
+};
+
+}  // namespace arc
+
+#endif  // COMPONENTS_ARC_ARC_VIDEO_SERVICE_H