Fix calling convention for Chromoting's NP_Shutdown entry points

remoting/host/host_plugin.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 <stdio.h>
 #include <string.h>
 
 #include <string>
 #include <vector>
 
@@ skipping 913 matching lines @@
     return NPERR_INCOMPATIBLE_VERSION_ERROR;
 
   g_at_exit_manager = new base::AtExitManager;
   g_npnetscape_funcs = npnetscape_funcs;
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
   NP_GetEntryPoints(nppfuncs);
 #endif
   return NPERR_NO_ERROR;
 }
 
-EXPORT NPError NP_Shutdown() {
+EXPORT NPError API_CALL NP_Shutdown() {
   LOG(INFO) << "NP_Shutdown";
   delete g_at_exit_manager;
   g_at_exit_manager = NULL;
   return NPERR_NO_ERROR;
 }
 
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
 EXPORT const char* API_CALL NP_GetMIMEDescription(void) {
   LOG(INFO) << "NP_GetMIMEDescription";
   return STRINGIZE(HOST_PLUGIN_MIME_TYPE) ":"
       HOST_PLUGIN_NAME ":"
       HOST_PLUGIN_DESCRIPTION;
 }
 
 EXPORT NPError API_CALL NP_GetValue(void* npp,
                                     NPPVariable variable,
                                     void* value) {
   return GetValue((NPP)npp, variable, value);
 }
 #endif
 
 }  // extern "C"