Create a new base/message_loop directory and move the message_loop_proxy.

base/message_loop.cc

 // Copyright (c) 2012 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 "base/message_loop.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/debug/alias.h"
 #include "base/debug/trace_event.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/message_loop_proxy_impl.h"
+#include "base/message_loop/message_loop_proxy_impl.h"
 #include "base/message_pump_default.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/statistics_recorder.h"
 #include "base/run_loop.h"
 #include "base/third_party/dynamic_annotations/dynamic_annotations.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/threading/thread_local.h"
 #include "base/time.h"
 #include "base/tracked_objects.h"
 
@@ skipping 779 matching lines @@
                                            Watcher *delegate) {
   return pump_libevent()->WatchFileDescriptor(
       fd,
       persistent,
       mode,
       controller,
       delegate);
 }
 
 #endif