Enable posting a message from JS to Android webview.

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_