ArcBridge: Rename VideoAcceleratorService to VideoDecodeAccelerator.

chrome/browser/chromeos/arc/video/gpu_arc_video_service_host.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 CHROME_BROWSER_CHROMEOS_ARC_VIDEO_GPU_ARC_VIDEO_SERVICE_HOST_H_
 #define CHROME_BROWSER_CHROMEOS_ARC_VIDEO_GPU_ARC_VIDEO_SERVICE_HOST_H_
 
 #include "base/macros.h"
 #include "components/arc/arc_service.h"
 #include "components/arc/common/video.mojom.h"
 #include "components/arc/instance_holder.h"
 #include "mojo/public/cpp/bindings/binding.h"
 
 namespace arc {
 
 class ArcBridgeService;
 
-// This class takes requests for creating channels of video accelerators from
-// arc::VideoInstance and forwards these requests to GpuArcVideoServce. It also
-// returns the created channels back to the arc::VideoInstance.
+// This class takes requests for accessing the VideoAcceleratorFactory, from
+// which video decode (or encode) accelerators could be created.
 //
-// This class is the proxy end of GpuArcVideoService and runs in the browser
-// process. The corresponding end "GpuArcVideoService" runs in the GPU process.
+// This class runs in the browser process, while the created instances of
+// VideoDecodeAccelerator or VideoEncodeAccelerator run in the GPU process.
 //
 // Lives on the UI thread.
 class GpuArcVideoServiceHost
     : public ArcService,
       public InstanceHolder<mojom::VideoInstance>::Observer,
       public mojom::VideoHost {
  public:
   explicit GpuArcVideoServiceHost(ArcBridgeService* bridge_service);
   ~GpuArcVideoServiceHost() override;
 
   // arc::InstanceHolder<mojom::VideoInstance>::Observer implementation.
   void OnInstanceReady() override;
 
   // arc::mojom::VideoHost implementation.
   void OnBootstrapVideoAcceleratorFactory(
       const OnBootstrapVideoAcceleratorFactoryCallback& callback) override;
 
  private:
   mojo::Binding<mojom::VideoHost> binding_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuArcVideoServiceHost);
 };
 
 }  // namespace arc
 
 #endif  // CHROME_BROWSER_CHROMEOS_ARC_VIDEO_GPU_ARC_VIDEO_SERVICE_HOST_H_