exo: Clean up cursor code

components/exo/wm_helper_ash.cc

 // Copyright 2016 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 "components/exo/wm_helper_ash.h"
 
 #include "ash/common/accessibility_delegate.h"
 #include "ash/common/system/tray/system_tray_notifier.h"
 #include "ash/common/wm/maximize_mode/maximize_mode_controller.h"
 #include "ash/common/wm_shell.h"
 #include "ash/shell.h"
 #include "base/memory/singleton.h"
 #include "ui/aura/client/focus_client.h"
 #include "ui/display/manager/display_manager.h"
 #include "ui/events/devices/device_data_manager.h"
 #include "ui/wm/public/activation_client.h"
 
 namespace exo {
 
 ////////////////////////////////////////////////////////////////////////////////
 // WMHelperAsh, public:
 
 WMHelperAsh::WMHelperAsh() {
   ash::Shell::GetInstance()->AddShellObserver(this);
   ash::Shell::GetInstance()->activation_client()->AddObserver(this);
+  ash::Shell::GetInstance()->cursor_manager()->AddObserver(this);
   ash::WmShell::Get()->AddDisplayObserver(this);
   aura::client::FocusClient* focus_client =
       aura::client::GetFocusClient(ash::Shell::GetPrimaryRootWindow());
   focus_client->AddObserver(this);
   ui::DeviceDataManager::GetInstance()->AddObserver(this);
   ash::Shell::Get()->system_tray_notifier()->AddAccessibilityObserver(this);
 }
 
 WMHelperAsh::~WMHelperAsh() {
   if (!ash::Shell::HasInstance())
     return;
   aura::client::FocusClient* focus_client =
       aura::client::GetFocusClient(ash::Shell::GetPrimaryRootWindow());
   focus_client->RemoveObserver(this);
   ash::WmShell::Get()->RemoveDisplayObserver(this);
+  ash::Shell::GetInstance()->cursor_manager()->RemoveObserver(this);
   ash::Shell::GetInstance()->activation_client()->RemoveObserver(this);
   ash::Shell::GetInstance()->RemoveShellObserver(this);
   ui::DeviceDataManager::GetInstance()->RemoveObserver(this);
   ash::Shell::Get()->system_tray_notifier()->RemoveAccessibilityObserver(this);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // WMHelperAsh, private:
 
 const display::ManagedDisplayInfo WMHelperAsh::GetDisplayInfo(
@@ skipping 97 matching lines @@
 
 void WMHelperAsh::OnDisplayConfigurationChanged() {
   NotifyDisplayConfigurationChanged();
 }
 
 void WMHelperAsh::OnKeyboardDeviceConfigurationChanged() {
   NotifyKeyboardDeviceConfigurationChanged();
 }
 
 }  // namespace exo