Update desktop tree when Aura windows are removed.

chrome/browser/ui/aura/accessibility/automation_manager_aura.cc

Index: chrome/browser/ui/aura/accessibility/automation_manager_aura.cc
diff --git a/chrome/browser/ui/aura/accessibility/automation_manager_aura.cc b/chrome/browser/ui/aura/accessibility/automation_manager_aura.cc
index c0de45ea7ab691ecf1d61069df35631d7e903f19..852d637b9464789b1649fcd571839c114249277d 100644
--- a/chrome/browser/ui/aura/accessibility/automation_manager_aura.cc
+++ b/chrome/browser/ui/aura/accessibility/automation_manager_aura.cc
@@ -17,7 +17,6 @@
 #include "content/public/browser/ax_event_notification_details.h"
 #include "content/public/browser/browser_context.h"
 #include "ui/aura/window.h"
-#include "ui/views/accessibility/ax_aura_obj_cache.h"
 #include "ui/views/accessibility/ax_aura_obj_wrapper.h"
 #include "ui/views/view.h"
 #include "ui/views/widget/widget.h"
@@ -41,6 +40,7 @@ void AutomationManagerAura::Enable(BrowserContext* context) {
   ResetSerializer();
 
   SendEvent(context, current_tree_->GetRoot(), ui::AX_EVENT_LOAD_COMPLETE);
+  views::AXAuraObjCache::GetInstance()->SetDelegate(this);
 
 #if defined(OS_CHROMEOS)
   aura::Window* active_window = ash::wm::GetActiveWindow();
@@ -121,6 +121,27 @@ void AutomationManagerAura::ShowContextMenu(int32_t id) {
   current_tree_->ShowContextMenu(id);
 }
 
+void AutomationManagerAura::OnChildWindowRemoved(
+    views::AXAuraObjWrapper* parent) {
+  if (!enabled_)
+    return;
+
+  BrowserContext* context = nullptr;
+  if (g_browser_process->profile_manager()) {
+    context = g_browser_process->profile_manager()->GetLastUsedProfile();

[dmazzoni, 2016/08/31 16:33:50]

This is done in two places. I think it'd be better if you just passed nullptr
instead of |context| to SendEvent, and did the same from
AutomationManagerAura::Enable, then have SendEvent be the one to call
GetLastUsedProfile if |context| is nullptr.

[David Tseng, 2016/08/31 21:06:42]

Done.

+  }
+
+  if (!context) {
+    LOG(WARNING) << "Accessibility notification but no browser context";
+    return;
+  }
+
+  if (!parent)
+    parent = current_tree_->GetRoot();
+
+  SendEvent(context, parent, ui::AX_EVENT_CHILDREN_CHANGED);
+}
+
 AutomationManagerAura::AutomationManagerAura()
     : enabled_(false), processing_events_(false) {}