arc: Fix crash in multi-user env on task stop.

chrome/browser/ui/ash/launcher/arc_app_window_launcher_controller.h

 // Copyright 2016 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.
 
 #ifndef CHROME_BROWSER_UI_ASH_LAUNCHER_ARC_APP_WINDOW_LAUNCHER_CONTROLLER_H_
 #define CHROME_BROWSER_UI_ASH_LAUNCHER_ARC_APP_WINDOW_LAUNCHER_CONTROLLER_H_
 
 #include <map>
 #include <memory>
 #include <vector>
@@ skipping 81 matching lines @@
       std::map<std::string, ArcAppWindowLauncherItemController*>;
 
   void StartObserving(Profile* profile);
   void StopObserving(Profile* profile);
 
   void RegisterApp(AppWindow* app_window);
   void UnregisterApp(AppWindow* app_window, bool close_controller);
 
   AppWindow* GetAppWindowForTask(int task_id);
 
-  void MayAttachContollerToWindow(aura::Window* window);
+  void AttachControllerToWindowIfNeeded(aura::Window* window);
+  void AttachControllerToWindowsIfNeeded();
 
   void SetOrientationLockForAppWindow(AppWindow* app_window);
 
   // AppWindowLauncherController:
   AppWindowLauncherItemController* ControllerForWindow(
       aura::Window* window) override;
 
   // Not owned
   ash::ShelfDelegate* shelf_delegate_;
   int active_task_id_ = -1;
   TaskIdToAppWindow task_id_to_app_window_;
   TaskIdToShelfAppIdMap task_id_to_shelf_app_id_;
   AppControllerMap app_controller_map_;
   std::vector<aura::Window*> observed_windows_;
   Profile* observed_profile_ = nullptr;
   bool observing_shell_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(ArcAppWindowLauncherController);
 };
 
 #endif  // CHROME_BROWSER_UI_ASH_LAUNCHER_ARC_APP_WINDOW_LAUNCHER_CONTROLLER_H_