Migrate more files to histogram_macros.h from histogram.h.

chrome/browser/sync_file_system/drive_backend/metadata_database.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 "chrome/browser/sync_file_system/drive_backend/metadata_database.h"
 
 #include <algorithm>
 #include <stack>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/scoped_vector.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/task_runner_util.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "chrome/browser/sync_file_system/drive_backend/drive_backend_constants.h"
 #include "chrome/browser/sync_file_system/drive_backend/drive_backend_util.h"
@@ skipping 1775 matching lines @@
       return false;
 
   if (!parents.empty())
     return false;
 
   return true;
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system