GpuArcVideoService

chrome/browser/chromeos/arc/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_GPU_ARC_VIDEO_SERVICE_HOST_H_
+#define CHROME_BROWSER_CHROMEOS_ARC_GPU_ARC_VIDEO_SERVICE_HOST_H_
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/threading/thread_checker.h"
+#include "components/arc/arc_bridge_service.h"
+#include "components/arc/arc_service.h"
+#include "components/arc/common/video.mojom.h"
+#include "mojo/public/cpp/bindings/binding.h"
+#include "mojo/public/cpp/bindings/interface_ptr_info.h"
+
+namespace base {
+class SingleThreadTaskRunner;
+}
+
+namespace arc {
+
+// This class passes requests from arc::VideoInstance to GpuArcVideoService to

[Owen Lin, 2016/03/14 08:45:52]

s/passes/takes/

How aobut:
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.

[kcwu, 2016/03/14 12:55:49]

Done.

+// create a video accelerator channel in GPU process and reply the created
+// channel.
+//
+// Don't be confused two senses of "host" of this class. This class, which
+// implements arc::VideoHost, handles requests from arc::VideoInstance. At the
+// same time, as its name says, this class is the host of corresponding class,
+// GpuArcVideoService, in the GPU process.

[Owen Lin, 2016/03/14 08:45:52]

I don't think this comment helps. I would suggest only keep the comments about
relation of this class and GpuArcVideoService.

For example,

This class is the proxy end of GpuArcVideoService and runs in the browser
process. The corresponding end "GpuArcVideoService" runs in the GPU process.

[kcwu, 2016/03/14 12:55:49]

Done.

+class GpuArcVideoServiceHost : public arc::ArcService,
+                               public arc::ArcBridgeService::Observer,
+                               public arc::VideoHost {
+ public:
+  explicit GpuArcVideoServiceHost(arc::ArcBridgeService* bridge_service);
+  ~GpuArcVideoServiceHost() override;
+
+  // arc::ArcBridgeService::Observer implementation.
+  void OnVideoInstanceReady() override;
+  void OnVideoInstanceClosed() override;
+
+  // arc::VideoHost implementation.
+  void OnRequestArcVideoAcceleratorChannel(
+      uint32_t pid,
+      const OnRequestArcVideoAcceleratorChannelCallback& callback) override;
+
+ private:
+  void BindServiceAndCreateChannel(
+      uint32_t pid,
+      const OnRequestArcVideoAcceleratorChannelCallback& callback,
+      mojo::InterfacePtrInfo<arc::VideoHost>* ptr_info);
+
+  base::ThreadChecker thread_checker_;
+
+  mojo::Binding<arc::VideoHost> binding_;
+
+  // IO task runner, where GpuProcessHost tasks run.
+  scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
+
+  arc::VideoHostPtr service_ptr_;
+
+  base::WeakPtrFactory<GpuArcVideoServiceHost> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(GpuArcVideoServiceHost);
+};
+
+}  // namespace arc
+
+#endif  // CHROME_BROWSER_CHROMEOS_ARC_GPU_ARC_VIDEO_SERVICE_HOST_H_