Use a direct include of the message_loop header in ppapi/, printing/, rlz/, sync/.

sync/tools/testserver/run_sync_testserver.cc

 // Copyright 2013 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 "base/at_exit.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
-#include "base/message_loop.h"
+#include "base/message_loop/message_loop.h"
 #include "base/process_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/test/test_timeouts.h"
 #include "net/test/python_utils.h"
 #include "sync/test/local_sync_test_server.h"
 
 static void PrintUsage() {
   printf("run_sync_testserver [--port=<port>] [--xmpp-port=<xmpp_port>]\n");
 }
 
@@ skipping 89 matching lines @@
     printf("Error: failed to start python sync test server. Exiting.\n");
     return -1;
   }
 
   printf("Python sync test server running at %s (type ctrl+c to exit)\n",
          test_server->host_port_pair().ToString().c_str());
 
   message_loop.Run();
   return 0;
 }