Update desktop tree when Aura windows are removed.

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 56 matching lines @@
 
 void AXAuraObjCache::Remove(Widget* widget) {
   RemoveInternal(widget, widget_to_id_map_);
 
   // When an entire widget is deleted, it doesn't always send a notification
   // on each of its views, so we need to explore them recursively.
   if (widget->GetRootView())
     RemoveViewSubtree(widget->GetRootView());
 }
 
-void AXAuraObjCache::Remove(aura::Window* window) {
+void AXAuraObjCache::Remove(aura::Window* window, aura::Window* parent) {
+  int id = GetIDInternal(parent, window_to_id_map_);
+  AXAuraObjWrapper* parent_window_obj = Get(id);
   RemoveInternal(window, window_to_id_map_);
+  if (parent && delegate_)
+    delegate_->OnChildWindowRemoved(parent_window_obj);
 }
 
 AXAuraObjWrapper* AXAuraObjCache::Get(int32_t id) {
   std::map<int32_t, AXAuraObjWrapper*>::iterator it = cache_.find(id);
 
   if (it == cache_.end())
     return NULL;
 
   return it->second;
 }
@@ skipping 21 matching lines @@
 AXAuraObjWrapper* AXAuraObjCache::GetFocus() {
   View* focused_view = GetFocusedView();
   if (focused_view)
     return GetOrCreate(focused_view);
   return nullptr;
 }
 
 AXAuraObjCache::AXAuraObjCache()
     : current_id_(1),
       focus_client_(nullptr),
-      is_destroying_(false) {
-}
+      is_destroying_(false),
+      delegate_(nullptr) {}
 
 AXAuraObjCache::~AXAuraObjCache() {
   is_destroying_ = true;
   base::STLDeleteContainerPairSecondPointers(cache_.begin(), cache_.end());
   cache_.clear();
 }
 
 View* AXAuraObjCache::GetFocusedView() {
   if (!focus_client_)
     return nullptr;
@@ skipping 71 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