Delete desktop/shell instance correctly when chrome is shutting down

ui/aura_shell/shell.cc

 // Copyright (c) 2011 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/aura_shell/shell.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "ui/aura/aura_switches.h"
 #include "ui/aura/client/aura_constants.h"
@@ skipping 109 matching lines @@
 }
 
 Shell::~Shell() {
   RemoveDesktopEventFilter(accelerator_filter_.get());
 
   // ShellTooltipManager needs a valid shell instance. We delete it before
   // deleting the shell |instance_|.
   RemoveDesktopEventFilter(tooltip_manager_.get());
   aura::Desktop::GetInstance()->SetProperty(aura::kDesktopTooltipClientKey,
       NULL);
+
+  // Make sure we delete WorkspaceController before launcher is
+  // deleted as it has a reference to launcher model.
+  workspace_controller_.reset();
+  launcher_.reset();
+
+  // Delete containers now so that child windows does not access
+  // observers when they are destructed. This has to be after launcher
+  // is destructed because launcher closes the widget in its destructor.
+  aura::Desktop* desktop_window = aura::Desktop::GetInstance();
+  while (!desktop_window->children().empty()) {
+    aura::Window* child = desktop_window->children()[0];
+    delete child;
+  }
+
   tooltip_manager_.reset();
 
   // Drag drop controller needs a valid shell instance. We destroy it first.
   drag_drop_controller_.reset();
 
   DCHECK(instance_ == this);
   instance_ = NULL;
-
-  // Make sure we delete WorkspaceController before launcher is
-  // deleted as it has a reference to launcher model.
-  workspace_controller_.reset();
 }
 
 // static
 Shell* Shell::CreateInstance(ShellDelegate* delegate) {
   CHECK(!instance_);
   instance_ = new Shell(delegate);
   instance_->Init();
   return instance_;
 }
 
 // static
 Shell* Shell::GetInstance() {
   DCHECK(instance_);
   return instance_;
 }
 
 // static
-void Shell::DeleteInstanceForTesting() {
+void Shell::DeleteInstance() {
   delete instance_;
   instance_ = NULL;
 }
 
 void Shell::Init() {
   aura::Desktop* desktop_window = aura::Desktop::GetInstance();
   desktop_window->SetCursor(aura::kCursorPointer);
 
   aura::Window::Windows containers;
   CreateSpecialContainers(&containers);
@@ skipping 100 matching lines @@
       new internal::WorkspaceController(default_container));
   workspace_controller_->SetLauncherModel(launcher_->model());
   default_container->SetEventFilter(
       new internal::DefaultContainerEventFilter(default_container));
   default_container->SetLayoutManager(
       new internal::DefaultContainerLayoutManager(
           workspace_controller_->workspace_manager()));
 }
 
 }  // namespace aura_shell