Add client and host dispatchers for video_stats channel to send video stats from host to client.

remoting/protocol/channel_dispatcher_base.h

 // Copyright (c) 2012 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 REMOTING_PROTOCOL_CHANNEL_DISPATCHER_BASE_H_
 #define REMOTING_PROTOCOL_CHANNEL_DISPATCHER_BASE_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 22 matching lines @@
     virtual ~EventHandler() {}
 
     // Called after the channel is initialized.
     virtual void OnChannelInitialized(
         ChannelDispatcherBase* channel_dispatcher) = 0;
 
     // Called after the channel is closed.
     virtual void OnChannelClosed(ChannelDispatcherBase* channel_dispatcher) = 0;
   };
 
-  // The callback is called when initialization is finished. The
-  // parameter is set to true on success.
-  typedef base::Callback<void(bool)> InitializedCallback;
-
   ~ChannelDispatcherBase() override;
 
   // Creates and connects the channel using |channel_factory|.
   void Init(MessageChannelFactory* channel_factory,
             EventHandler* event_handler);
 
   // Initializes the channel using |message_pipe| that's already connected.
   void Init(std::unique_ptr<MessagePipe> message_pipe,
             EventHandler* event_handler);
 
   const std::string& channel_name() { return channel_name_; }
 
   // Returns true if the channel is currently connected.
   bool is_connected() { return is_connected_; }
 
  protected:
-  explicit ChannelDispatcherBase(const char* channel_name);
+  explicit ChannelDispatcherBase(const std::string& channel_name);
 
   MessagePipe* message_pipe() { return message_pipe_.get(); }
 
   // Child classes must override this method to handle incoming messages.
   virtual void OnIncomingMessage(std::unique_ptr<CompoundBuffer> message) = 0;
 
  private:
   void OnChannelReady(std::unique_ptr<MessagePipe> message_pipe);
 
   // MessagePipe::EventHandler interface.
   void OnMessagePipeOpen() override;
   void OnMessageReceived(std::unique_ptr<CompoundBuffer> message) override;
   void OnMessagePipeClosed() override;
 
   std::string channel_name_;
   MessageChannelFactory* channel_factory_ = nullptr;
   EventHandler* event_handler_ = nullptr;
   bool is_connected_ = false;
 
   std::unique_ptr<MessagePipe> message_pipe_;
 
   DISALLOW_COPY_AND_ASSIGN(ChannelDispatcherBase);
 };
 
 }  // namespace protocol
 }  // namespace remoting
 
 #endif  // REMOTING_PROTOCOL_CHANNEL_DISPATCHER_BASE_H_