Add support for dynamic channels in WebrtcTransport.

remoting/protocol/channel_dispatcher_base.cc

Index: remoting/protocol/channel_dispatcher_base.cc
diff --git a/remoting/protocol/channel_dispatcher_base.cc b/remoting/protocol/channel_dispatcher_base.cc
index 274c0d5a58dffc4c1695bfca77cfc85dac32b888..97f3be5e4857ae9076d177b159acdea79b33658d 100644
--- a/remoting/protocol/channel_dispatcher_base.cc
+++ b/remoting/protocol/channel_dispatcher_base.cc
@@ -31,15 +31,29 @@ void ChannelDispatcherBase::Init(MessageChannelFactory* channel_factory,
       &ChannelDispatcherBase::OnChannelReady, base::Unretained(this)));
 }
 
+void ChannelDispatcherBase::Init(std::unique_ptr<MessagePipe> message_pipe,
+                                 EventHandler* event_handler) {
+  event_handler_ = event_handler;
+  OnChannelReady(std::move(message_pipe));
+}
+
 void ChannelDispatcherBase::OnChannelReady(
     std::unique_ptr<MessagePipe> message_pipe) {
   channel_factory_ = nullptr;
   message_pipe_ = std::move(message_pipe);
-  message_pipe_->StartReceiving(base::Bind(
-      &ChannelDispatcherBase::OnIncomingMessage, base::Unretained(this)));
+  message_pipe_->Start(this);
 
   event_handler_->OnChannelInitialized(this);
 }
 
+void ChannelDispatcherBase::OnMessageReceived(
+    std::unique_ptr<CompoundBuffer> message) {
+  OnIncomingMessage(std::move(message));
+}
+
+void ChannelDispatcherBase::OnMessagePipeClosed() {
+  event_handler_->OnChannelClosed(this);
+}
+
 }  // namespace protocol
 }  // namespace remoting