Optionally have MessagePort pass data as base::Value, part 1.

content/browser/message_port_provider.cc

 // Copyright 2014 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.
 
 #include "content/public/browser/message_port_provider.h"
 
 #include "base/basictypes.h"
 #include "content/browser/browser_thread_impl.h"
 #include "content/browser/message_port_message_filter.h"
 #include "content/browser/message_port_service.h"
@@ skipping 64 matching lines @@
   // port numbers.
   msp->UpdateMessagePort(*port1, delegate, *port1);
   msp->UpdateMessagePort(*port2, delegate, *port2);
   msp->Entangle(*port1, *port2);
   msp->Entangle(*port2, *port1);
 }
 
 // static
 void MessagePortProvider::PostMessageToPort(
     int sender_port_id,
-    const base::string16& data,
+    const MessagePortMessage& message,
     const std::vector<int>& sent_ports) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   MessagePortService* msp = MessagePortService::GetInstance();
-  msp->PostMessage(sender_port_id, data, sent_ports);
+  msp->PostMessage(sender_port_id, message, sent_ports);
 }
 
 // static
 void MessagePortProvider::OnMessagePortDelegateClosing(
     MessagePortDelegate* delegate) {
   MessagePortService::GetInstance()->OnMessagePortDelegateClosing(delegate);
 }
 
 } // namespace content