Implement GpuArcVideoService for arc video accelerator

content/common/gpu/media/gpu_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 CONTENT_COMMON_GPU_MEDIA_GPU_ARC_VIDEO_SERVICE_H_
+#define CONTENT_COMMON_GPU_MEDIA_GPU_ARC_VIDEO_SERVICE_H_
+
+#include <map>
+
+#include "base/callback.h"
+#include "base/threading/thread_checker.h"
+
+namespace base {
+class SingleThreadTaskRunner;
+class WaitableEvent;
+}
+
+namespace IPC {
+struct ChannelHandle;
+}
+
+namespace content {
+
+// GpuArcVideoService manages life-cycle and IPC message translation for
+// ArcVideoAccelerator.
+//
+// For each creation request from GpuChannelManager, GpuArcVideoService will
+// create a new IPC channel.
+class GpuArcVideoService {
+ public:
+  class AcceleratorStub;
+  using CreateChannelCallback = base::Callback<void(const IPC::ChannelHandle&)>;
+
+  // |shutdown_event| should signal an event when this process is about to be
+  // shut down in order to notify our new IPC channel to terminate.
+  GpuArcVideoService(
+      base::WaitableEvent* shutdown_event,
+      const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner);
+
+  // Upon deletion, all ArcVideoAccelerator will be deleted and the associated
+  // IPC channels are closed.
+  ~GpuArcVideoService();
+
+  // Creates a new accelerator stub. The creation result will be sent back via
+  // |callback|.
+  void CreateChannel(const CreateChannelCallback& callback);
+
+  // Removes the reference of |stub| (and trigger deletion) from this class.
+  void RemoveClient(AcceleratorStub* stub);
+
+ private:
+  base::ThreadChecker thread_checker_;
+
+  // Shutdown event of GPU process.
+  base::WaitableEvent* shutdown_event_;
+
+  // GPU io thread task runner.
+  scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
+
+  // Bookkeeping all accelerator stubs.
+  std::map<AcceleratorStub*, scoped_ptr<AcceleratorStub>> accelerator_stubs_;
+
+  DISALLOW_COPY_AND_ASSIGN(GpuArcVideoService);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_GPU_MEDIA_GPU_ARC_VIDEO_SERVICE_H_