Added JsonMessage to the control channel.

remoting/client/chromoting_client.cc

Index: remoting/client/chromoting_client.cc
diff --git a/remoting/client/chromoting_client.cc b/remoting/client/chromoting_client.cc
index 2d308c92c47a875d67ad1b1dc6b15b78a88a84ef..f87d9e8dccd74534e985e24f53e6e6c495f8e46b 100644
--- a/remoting/client/chromoting_client.cc
+++ b/remoting/client/chromoting_client.cc
@@ -119,6 +119,13 @@ void ChromotingClient::SetPairingResponse(
   user_interface_->SetPairingResponse(pairing_response);
 }
 
+void ChromotingClient::DeliverHostMessage(
+    const protocol::ExtensionMessage& message) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+
+  user_interface_->DeliverHostMessage(message);
+}
+
 void ChromotingClient::InjectClipboardEvent(
     const protocol::ClipboardEvent& event) {
   DCHECK(task_runner_->BelongsToCurrentThread());