Migrate chrome/browser files to histogram_macros.h includes.

chrome/browser/background/background_mode_manager.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 "chrome/browser/background/background_mode_manager.h"
 
 #include <stddef.h>
 #include <algorithm>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/base_paths.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/location.h"
 #include "base/logging.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/background/background_application_list_model.h"
 #include "chrome/browser/background/background_mode_optimizer.h"
 #include "chrome/browser/background/background_trigger.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_shutdown.h"
@@ skipping 1017 matching lines @@
     }
   }
   return profile_it;
 }
 
 bool BackgroundModeManager::IsBackgroundModePrefEnabled() const {
   PrefService* service = g_browser_process->local_state();
   DCHECK(service);
   return service->GetBoolean(prefs::kBackgroundModeEnabled);
 }