Converts DockedWindowLayoutManager to common ash/wm types

ash/shell.cc

 // Copyright (c) 2012 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/shell.h"
 
 #include <algorithm>
 #include <string>
 #include <utility>
 
@@ skipping 203 matching lines @@
 }
 
 // static
 bool Shell::HasInstance() {
   return !!instance_;
 }
 
 // static
 void Shell::DeleteInstance() {
   delete instance_;
-  instance_ = nullptr;
 }
 
 // static
 RootWindowController* Shell::GetPrimaryRootWindowController() {
   CHECK(HasInstance());
   return GetRootWindowController(GetPrimaryRootWindow());
 }
 
 // static
 Shell::RootWindowControllerList Shell::GetAllRootWindowControllers() {
@@ skipping 575 matching lines @@
   audio_a11y_controller_.reset();
 #endif  // defined(OS_CHROMEOS)
 
   // This also deletes all RootWindows. Note that we invoke Shutdown() on
   // WindowTreeHostManager before resetting |window_tree_host_manager_|, since
   // destruction
   // of its owned RootWindowControllers relies on the value.
   display_manager_->CreateScreenForShutdown();
   display_configuration_controller_.reset();
 
+  // Needs to happen before |window_tree_host_manager_|. Calls back to Shell, so
+  // also needs to be destroyed before |instance_| reset to null.
+  wm_globals_.reset();
+
   // Depends on |focus_client_|, so must be destroyed before.
   window_tree_host_manager_->Shutdown();
   window_tree_host_manager_.reset();
   focus_client_.reset();
   screen_position_controller_.reset();
   accessibility_delegate_.reset();
   new_window_delegate_.reset();
   media_delegate_.reset();
 
   keyboard::KeyboardController::ResetInstance(nullptr);
@@ skipping 399 matching lines @@
 
 void Shell::OnWindowActivated(
     aura::client::ActivationChangeObserver::ActivationReason reason,
     aura::Window* gained_active,
     aura::Window* lost_active) {
   if (gained_active)
     target_root_window_ = gained_active->GetRootWindow();
 }
 
 }  // namespace ash