Fixing notification message crash on fast dismissal click

ash/system/user/user_view.cc

 // Copyright 2014 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 "ash/system/user/user_view.h"
 
 #include <algorithm>
 
 #include "ash/multi_profile_uma.h"
 #include "ash/popup_message.h"
@@ skipping 193 matching lines @@
 UserView::UserView(SystemTrayItem* owner,
                    user::LoginStatus login,
                    MultiProfileIndex index,
                    bool for_detailed_view)
     : multiprofile_index_(index),
       user_card_view_(NULL),
       owner_(owner),
       is_user_card_button_(false),
       logout_button_(NULL),
       add_user_disabled_(false),
-      for_detailed_view_(for_detailed_view) {
+      for_detailed_view_(for_detailed_view),
+      focus_manager_(NULL) {
   CHECK_NE(user::LOGGED_IN_NONE, login);
   if (!index) {
     // Only the logged in user will have a background. All other users will have
     // to allow the TrayPopupContainer highlighting the menu line.
     set_background(views::Background::CreateSolidBackground(
         login == user::LOGGED_IN_PUBLIC ? kPublicAccountBackgroundColor
                                         : kBackgroundColor));
   }
   SetLayoutManager(new views::BoxLayout(
       views::BoxLayout::kHorizontal, 0, 0, kTrayPopupPaddingBetweenItems));
@@ skipping 301 matching lines @@
     }
   }
   // Find the screen area which encloses both elements and sets then a mouse
   // watcher which will close the "menu".
   gfx::Rect area = user_card_view_->GetBoundsInScreen();
   area.set_height(2 * area.height());
   mouse_watcher_.reset(
       new views::MouseWatcher(new UserViewMouseWatcherHost(area), this));
   mouse_watcher_->Start();
   // Install a listener to focus changes so that we can remove the card when
-  // the focus gets changed.
-  user_card_view_->GetFocusManager()->AddFocusChangeListener(this);
+  // the focus gets changed. When called through the destruction of the bubble,
+  // the FocusManager cannot be determined anymore and we remember it here.
+  focus_manager_ = user_card_view_->GetFocusManager();
+  focus_manager_->AddFocusChangeListener(this);
 }
 
 void UserView::RemoveAddUserMenuOption() {
   if (!add_menu_option_.get())
     return;
-  user_card_view_->GetFocusManager()->RemoveFocusChangeListener(this);
-  user_card_view_->GetFocusManager()->ClearFocus();
+  focus_manager_->RemoveFocusChangeListener(this);
+  focus_manager_ = NULL;
+  if (user_card_view_->GetFocusManager())
+    user_card_view_->GetFocusManager()->ClearFocus();
   popup_message_.reset();
   mouse_watcher_.reset();
   add_menu_option_.reset();
 }
 
 }  // namespace tray
 }  // namespace ash