Enable messaging over a navigator.connect initiated channel.

content/browser/message_port_delegate.h

+// 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.
+
+#ifndef CONTENT_BROWSER_MESSAGE_PORT_DELEGATE_H_
+#define CONTENT_BROWSER_MESSAGE_PORT_DELEGATE_H_
+
+#include <vector>
+#include "base/strings/string16.h"
+
+namespace content {
+
+// Delegate used by MessagePortService to send messages to message ports to the
+// correct renderer. Delegates are responsible for managing their own lifetime,
+// and should call MessagePortService::OnMessagePortDelegateClosing if they are
+// destroyed while there are still message ports associated with them.
+class MessagePortDelegate {
+ public:
+  // Sends a message to the given route. Implementations are responsible for
+  // updating MessagePortService with new routes for the sent message ports.
+  virtual void SendMessage(int route_id,
+                           const base::string16& message,
+                           const std::vector<int>& sent_message_port_ids) = 0;
+
+  // Sends a "messages are queued" IPC to the given route.
+  virtual void SendMessagesAreQueued(int route_id) = 0;
+
+ protected:
+  virtual ~MessagePortDelegate() {}
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_MESSAGE_PORT_DELEGATE_H_