ServiceWorker: Release a reference when it fails to dispatch ExtendableMessageEvent

content/browser/message_port_service.h

 // Copyright 2013 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_SERVICE_H_
 #define CONTENT_BROWSER_MESSAGE_PORT_SERVICE_H_
 
 #include <map>
 #include <utility>
 #include <vector>
@@ skipping 49 matching lines @@
   // code doing that isn't able to immediately update the message port with a
   // new filter and routing_id. This queues up all messages sent to this port
   // until later ReleaseMessages is called for this port (this will happen
   // automatically as soon as a WebMessagePortChannelImpl instance is created
   // for this port in the renderer. The browser side code is still responsible
   // for updating the port with a new filter before that happens. If ultimately
   // transfering the port to a new process fails, ClosePort should be called to
   // clean up the port.
   void HoldMessages(int message_port_id);
 
+  // Returns true if messages for a message port are on hold.
+  bool AreMessagesHeld(int message_port_id);
+
   // Closes and cleans up the message port.
   void ClosePort(int message_port_id);
 
   void OnMessagePortDelegateClosing(MessagePortDelegate* filter);
 
   // Attempts to send the queued messages for a message port.
   void SendQueuedMessagesIfPossible(int message_port_id);
 
  private:
   friend struct base::DefaultSingletonTraits<MessagePortService>;
@@ skipping 16 matching lines @@
 
   // We need globally unique identifiers for each message port.
   int next_message_port_id_;
 
   DISALLOW_COPY_AND_ASSIGN(MessagePortService);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_MESSAGE_PORT_SERVICE_H_