Add the plumbing that will carry a clipboard item from a chromoting client to a host.

remoting/base/constants.cc

 // Copyright (c) 2011 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 "remoting/base/constants.h"
 
 namespace remoting {
 
 const char kChromotingBotJid[] = "remoting@bot.talk.google.com";
 
 const char kChromotingTokenDefaultServiceName[] = "chromiumsync";
 
 const char kChromotingXmlNamespace[] = "google:remoting";
 
 const char kControlChannelName[] = "control";
 const char kEventChannelName[] = "event";
 const char kVideoChannelName[] = "video";
 const char kVideoRtpChannelName[] = "videortp";
 const char kVideoRtcpChannelName[] = "videortpc";
 
+const char kMimeTypeText[] = "text/plain; charset=UTF-8";
+
 }  // namespace remoting