Rename IPC Sender and Listener in ppapi, content/public, and content/renderer

ppapi/proxy/ppb_pdf_proxy.h

 // 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.
 
 #ifndef PPAPI_PPB_PDF_PROXY_H_
 #define PPAPI_PPB_PDF_PROXY_H_
 
+#include <string>
+
 #include "ppapi/c/pp_module.h"
 #include "ppapi/proxy/interface_proxy.h"
 #include "ppapi/shared_impl/host_resource.h"
 
 struct PPB_PDF;
 
 namespace ppapi {
 namespace proxy {
 
 struct SerializedFontDescription;
@@ skipping 21 matching lines @@
   // When this proxy is in the host side, this value caches the interface
   // pointer so we don't have to retrieve it from the dispatcher each time.
   // In the plugin, this value is always NULL.
   const PPB_PDF* ppb_pdf_impl_;
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PPB_PDF_PROXY_H_