Add trace code to track all posted tasks in message_loop.

chrome/browser/sync/util/logging.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 "chrome/browser/sync/util/logging.h"
 
 #include "base/tracked.h"
 
 namespace browser_sync {
 
 bool VlogIsOnForLocation(const tracked_objects::Location& from_here,
                          int verbose_level) {
+  const base::StringPiece& file = from_here.file_name();
   return (verbose_level <=
           logging::GetVlogLevelHelper(
-              from_here.file_name(), ::strlen(from_here.file_name())));
+              file.data(), file.size() + 1));
 }
 
 }  // namespace browser_sync