AXAuraObjCache - clear focus client reference when window is destroyed

ui/views/accessibility/ax_aura_obj_cache.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 "ui/views/accessibility/ax_aura_obj_cache.h"
 
 #include "base/memory/singleton.h"
 #include "base/stl_util.h"
 #include "ui/aura/client/focus_client.h"
 #include "ui/aura/window.h"
@@ skipping 17 matching lines @@
 
 AXAuraObjWrapper* AXAuraObjCache::GetOrCreate(Widget* widget) {
   return CreateInternal<AXWidgetObjWrapper>(widget, widget_to_id_map_);
 }
 
 AXAuraObjWrapper* AXAuraObjCache::GetOrCreate(aura::Window* window) {
   if (!focus_client_) {
     aura::Window* root_window = window->GetRootWindow();
     if (root_window) {
       focus_client_ = aura::client::GetFocusClient(root_window);
+      root_window->AddObserver(this);
       if (focus_client_)
         focus_client_->AddObserver(this);
     }
   }
   return CreateInternal<AXWindowObjWrapper>(window, window_to_id_map_);
 }
 
 int32_t AXAuraObjCache::GetID(View* view) const {
   return GetIDInternal(view, view_to_id_map_);
 }
@@ skipping 104 matching lines @@
   return focus_manager->GetFocusedView();
 }
 
 void AXAuraObjCache::OnWindowFocused(aura::Window* gained_focus,
                                      aura::Window* lost_focus) {
   View* view = GetFocusedView();
   if (view)
     view->NotifyAccessibilityEvent(ui::AX_EVENT_FOCUS, true);
 }
 
+void AXAuraObjCache::OnWindowDestroying(aura::Window* window) {
+  focus_client_ = nullptr;
+}
+
 template <typename AuraViewWrapper, typename AuraView>
 AXAuraObjWrapper* AXAuraObjCache::CreateInternal(
     AuraView* aura_view,
     std::map<AuraView*, int32_t>& aura_view_to_id_map) {
   if (!aura_view)
     return NULL;
 
   typename std::map<AuraView*, int32_t>::iterator it =
       aura_view_to_id_map.find(aura_view);
 
@@ skipping 26 matching lines @@
     AuraView* aura_view,
     std::map<AuraView*, int32_t>& aura_view_to_id_map) {
   int32_t id = GetID(aura_view);
   if (id == -1)
     return;
   aura_view_to_id_map.erase(aura_view);
   Remove(id);
 }
 
 }  // namespace views