Revert of Merge apps/pref* to extensions/browser/pref*

chrome/browser/ui/app_list/app_list_service_impl.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/ui/app_list/app_list_service_impl.h"
 
 #include <string>
 
+#include "apps/pref_names.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/string16.h"
 #include "base/time/time.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_shutdown.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/ui/app_list/profile_loader.h"
@@ skipping 340 matching lines @@
   if (!base::MessageLoop::current())
     return;  // In a unit test.
 
   // Send app list usage stats after a delay.
   const int kSendUsageStatsDelay = 5;
   base::MessageLoop::current()->PostDelayedTask(
       FROM_HERE,
       base::Bind(&AppListServiceImpl::SendAppListStats),
       base::TimeDelta::FromSeconds(kSendUsageStatsDelay));
 }