Added JsonMessage to the control channel.

remoting/client/plugin/chromoting_instance.cc

Index: remoting/client/plugin/chromoting_instance.cc
diff --git a/remoting/client/plugin/chromoting_instance.cc b/remoting/client/plugin/chromoting_instance.cc
index 8be169c9d227874a17b053e262cd7db27e4054d5..e22452a42168a49837568a94509d703a6ae00c2c 100644
--- a/remoting/client/plugin/chromoting_instance.cc
+++ b/remoting/client/plugin/chromoting_instance.cc
@@ -144,7 +144,7 @@ logging::LogMessageHandlerFunction g_logging_old_handler = NULL;
 const char ChromotingInstance::kApiFeatures[] =
     "highQualityScaling injectKeyEvent sendClipboardItem remapKey trapKey "
     "notifyClientDimensions notifyClientResolution pauseVideo pauseAudio "
-    "asyncPin thirdPartyAuth pinlessAuth";
+    "asyncPin thirdPartyAuth pinlessAuth extensionMessage";
 
 const char ChromotingInstance::kRequestedCapabilities[] = "";
 const char ChromotingInstance::kSupportedCapabilities[] = "desktopShape";
@@ -433,6 +433,13 @@ void ChromotingInstance::HandleMessage(const pp::Var& message) {
       return;
     }
     RequestPairing(client_name);
+  } else if (method == "extensionMessage") {
+    std::string type, message;
+    if (!data->GetString("type", &type) || !data->GetString("data", &message)) {
+      LOG(ERROR) << "Invalid extensionMessage.";
+      return;
+    }
+    SendClientMessage(type, message);
   }
 }
 
@@ -537,6 +544,14 @@ void ChromotingInstance::SetPairingResponse(
   PostChromotingMessage("pairingResponse", data.Pass());
 }
 
+void ChromotingInstance::DeliverHostMessage(
+    const protocol::ExtensionMessage& message) {
+  scoped_ptr<base::DictionaryValue> data(new base::DictionaryValue());
+  data->SetString("type", message.type());
+  data->SetString("data", message.data());
+  PostChromotingMessage("extensionMessage", data.Pass());
+}
+
 void ChromotingInstance::FetchSecretFromDialog(
     bool pairing_supported,
     const protocol::SecretFetchedCallback& secret_fetched_callback) {
@@ -839,6 +854,17 @@ void ChromotingInstance::RequestPairing(const std::string& client_name) {
   host_connection_->host_stub()->RequestPairing(pairing_request);
 }
 
+void ChromotingInstance::SendClientMessage(const std::string& type,
+                                           const std::string& data) {
+  if (!IsConnected()) {
+    return;
+  }
+  protocol::ExtensionMessage message;
+  message.set_type(type);
+  message.set_data(data);
+  host_connection_->host_stub()->DeliverClientMessage(message);
+}
+
 ChromotingStats* ChromotingInstance::GetStats() {
   if (!client_.get())
     return NULL;