Properly queue messages sent to message ports that are transferred to a service worker.

content/child/webmessageportchannel_impl.cc

Index: content/child/webmessageportchannel_impl.cc
diff --git a/content/child/webmessageportchannel_impl.cc b/content/child/webmessageportchannel_impl.cc
index dbdc2f38eb66102d9b14ea952091ac530b7e976e..d9fb79e41d54e0cc31ad47f0aba4feb81f20c99c 100644
--- a/content/child/webmessageportchannel_impl.cc
+++ b/content/child/webmessageportchannel_impl.cc
@@ -165,6 +165,8 @@ void WebMessagePortChannelImpl::Init() {
     DCHECK(message_port_id_ == MSG_ROUTING_NONE);
     Send(new MessagePortHostMsg_CreateMessagePort(
         &route_id_, &message_port_id_));
+  } else if (message_port_id_ != MSG_ROUTING_NONE) {
+    Send(new MessagePortHostMsg_ReleaseMessages(message_port_id_));
   }
 
   ChildThread::current()->GetRouter()->AddRoute(route_id_, this);