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

ppapi/shared_impl/callback_tracker.cc

 // Copyright (c) 2010 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 "ppapi/shared_impl/callback_tracker.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
-#include "base/message_loop.h"
+#include "base/message_loop/message_loop.h"
 #include "ppapi/c/pp_completion_callback.h"
 #include "ppapi/shared_impl/tracked_callback.h"
 
 namespace ppapi {
 
 // CallbackTracker -------------------------------------------------------------
 
 CallbackTracker::CallbackTracker() {
 }
 
@@ skipping 43 matching lines @@
   CallbackSet::iterator it = map_it->second.find(tracked_callback);
   DCHECK(it != map_it->second.end());
   map_it->second.erase(it);
 
   // If there are no pending callbacks left for this ID, get rid of the entry.
   if (map_it->second.empty())
     pending_callbacks_.erase(map_it);
 }
 
 }  // namespace ppapi