FBTF: Fix more ctor/dtors found by clang plugin.

chrome/common/webmessageportchannel_impl.cc

 // Copyright (c) 2009 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 "chrome/common/webmessageportchannel_impl.h"
 
 #include "chrome/common/child_process.h"
 #include "chrome/common/child_thread.h"
 #include "chrome/common/worker_messages.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebString.h"
@@ skipping 217 matching lines @@
   }
 
   Send(new WorkerProcessHostMsg_SendQueuedMessages(
       message_port_id_, queued_messages));
 
   message_port_id_ = MSG_ROUTING_NONE;
 
   Release();
   ChildProcess::current()->ReleaseProcess();
 }
+
+WebMessagePortChannelImpl::Message::Message() {}
+
+WebMessagePortChannelImpl::Message::~Message() {}