cc:: Add remote mode to the compositor

cc/trees/remote_channel_host.h

Index: cc/trees/remote_channel_host.h
diff --git a/cc/trees/remote_channel_host.h b/cc/trees/remote_channel_host.h
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index 0000000000000000000000000000000000000000..08d4c99227365640080eea4e3264da82daede438
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+++ b/cc/trees/remote_channel_host.h
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+// 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 CC_TREES_REMOTE_CHANNEL_HOST_H_
+#define CC_TREES_REMOTE_CHANNEL_HOST_H_
+
+#include "base/macros.h"
+#include "base/threading/thread_checker.h"
+#include "cc/base/cc_export.h"
+#include "cc/raster/task_graph_runner.h"
+#include "cc/trees/remote_channel_host_client.h"
+#include "cc/trees/remote_channel_impl.h"
+#include "cc/trees/remote_proto_channel.h"
+
+namespace cc {
+
+// RemoteChannelHost owns and controls the lifetime of the RemoteChannelImpl.
+// For details, see cc/trees/remote_channel_impl.h.
+// This class is created and lives on the main thread.
+class CC_EXPORT RemoteChannelHost : public RemoteProtoChannel::ProtoReceiver {
+ public:
+  static scoped_ptr<RemoteChannelHost> Create(
+      RemoteProtoChannel* remote_proto_channel,
+      RemoteChannelHostClient* client,
+      TaskGraphRunner* task_graph_runner,
+      scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
+      scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner);
+
+  ~RemoteChannelHost() override;
+
+  // TODO(khushalsagar): Add APIs for handling output surface requests and
+  // visibility changes from the client.
+
+  // Called by RemoteChannelImpl.
+  void SendProto(const proto::CompositorMessage& proto);
+
+ protected:
+  RemoteChannelHost(
+      RemoteProtoChannel* remote_proto_channel,
+      RemoteChannelHostClient* client,
+      TaskGraphRunner* task_graph_runner,
+      scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
+      scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner);
+
+  // Virtual for testing.
+  virtual scoped_ptr<RemoteChannelImpl> CreateRemoteChannelImpl(
+      RemoteChannelHost* remote_channel_host,
+      TaskGraphRunner* task_graph_runner,
+      const LayerTreeSettings& settings,
+      scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
+      scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner);
+
+ private:
+  // RemoteProtoChannel::ProtoReceiver implementation.
+  void OnProtoReceived(scoped_ptr<proto::CompositorMessage> proto) override;
+
+  void InitializeImpl(const proto::InitializeImpl& proto);
+
+  RemoteProtoChannel* remote_proto_channel_;
+  RemoteChannelHostClient* client_;
+
+  // These hold a valid value only until the initialize message is received and
+  // the RemoteChannelImpl is created in Initialize().
+  TaskGraphRunner* task_graph_runner_;
+  scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
+  scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner_;
+
+  base::ThreadChecker main_thread_checker_;
+
+  scoped_ptr<RemoteChannelImpl> remote_channel_impl_;
+
+  // Set when a shutdown message is received and the RemoteChannelImpl is
+  // destroyed.
+  bool did_shutdown_;
+
+  DISALLOW_COPY_AND_ASSIGN(RemoteChannelHost);
+};
+
+}  // namespace cc
+
+#endif  // CC_TREES_REMOTE_CHANNEL_HOST_H_