Split ExtensionSystem interface from ExtensionSystemImpl implementation, part 1.

chrome/browser/extensions/extension_test_notification_observer.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/extensions/extension_test_notification_observer.h"
 
 #include "base/callback_list.h"
 #include "chrome/browser/extensions/extension_service.h"
-#include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/test/test_utils.h"
+#include "extensions/browser/extension_system.h"
 #include "extensions/browser/process_manager.h"
 #include "extensions/common/extension.h"
 
 using extensions::Extension;
 
 namespace {
 
 bool HasExtensionPageActionCountReachedTarget(LocationBarTesting* location_bar,
                                               int target_page_action_count) {
   VLOG(1) << "Number of page actions: " << location_bar->PageActionCount();
@@ skipping 253 matching lines @@
   case chrome::NOTIFICATION_EXTENSION_LOAD_ERROR:
     VLOG(1) << "Got EXTENSION_LOAD_ERROR notification.";
     ++extension_load_errors_observed_;
     break;
 
   default:
     NOTREACHED();
     break;
   }
 }