Split ExtensionSystem interface from ExtensionSystemImpl implementation, part 1.

chrome/browser/ui/app_list/extension_app_model_builder.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/ui/app_list/extension_app_model_builder.h"
 
 #include <algorithm>
 
 #include "base/auto_reset.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/extensions/extension_service.h"
-#include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/extensions/install_tracker.h"
 #include "chrome/browser/extensions/install_tracker_factory.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/app_list/app_list_controller_delegate.h"
 #include "chrome/browser/ui/app_list/app_list_syncable_service.h"
 #include "chrome/browser/ui/app_list/app_list_syncable_service_factory.h"
 #include "chrome/browser/ui/app_list/extension_app_item.h"
 #include "chrome/common/extensions/extension_constants.h"
 #include "chrome/common/pref_names.h"
 #include "content/public/browser/notification_service.h"
 #include "extensions/browser/extension_prefs.h"
+#include "extensions/browser/extension_system.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/extension_set.h"
 #include "ui/gfx/image/image_skia.h"
 
 using extensions::Extension;
 
 namespace {
 
 bool ShouldDisplayInAppLauncher(Profile* profile,
                                 scoped_refptr<const Extension> app) {
@@ skipping 254 matching lines @@
     app_list::AppListItem* item = item_list->item_at(idx + 1);
     if (item->GetItemType() == ExtensionAppItem::kItemType) {
       next = static_cast<ExtensionAppItem*>(item);
       break;
     }
   }
   // item->Move will call set_position, overriding the item's position.
   if (prev || next)
     static_cast<ExtensionAppItem*>(item)->Move(prev, next);
 }