Add {Lock,Unlock,Show,Hide}Cursor() to the window manager mojom.

ash/wm/lock_state_controller.cc

 // Copyright 2013 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/wm/lock_state_controller.h"
 
 #include <algorithm>
 #include <string>
 #include <utility>
 
@@ skipping 143 matching lines @@
     return;
   StartImmediatePreLockAnimation(false /* request_lock_on_completion */);
 }
 
 void LockStateController::RequestShutdown() {
   if (shutting_down_)
     return;
 
   shutting_down_ = true;
 
-  Shell* shell = Shell::Get();
-  // TODO(derat): Remove these null checks once mash instantiates a
-  // CursorManager.
-  if (shell->cursor_manager()) {
-    shell->cursor_manager()->HideCursor();
-    shell->cursor_manager()->LockCursor();
-  }
+  ShellPort* port = ShellPort::Get();
+  port->HideCursor();
+  port->LockCursor();
 
   animator_->StartAnimation(
       SessionStateAnimator::ROOT_CONTAINER,
       SessionStateAnimator::ANIMATION_GRAYSCALE_BRIGHTNESS,
       SessionStateAnimator::ANIMATION_SPEED_SHUTDOWN);
   StartRealShutdownTimer(true);
 }
 
 void LockStateController::OnLockScreenHide(base::OnceClosure callback) {
   StartUnlockAnimationBeforeUIDestroyed(std::move(callback));
@@ skipping 371 matching lines @@
     SessionStateAnimator::AnimationSpeed speed,
     SessionStateAnimator::AnimationSequence* animation_sequence) {
   if (unlocked_properties_.get() && unlocked_properties_->wallpaper_is_hidden) {
     animation_sequence->StartAnimation(SessionStateAnimator::WALLPAPER,
                                        SessionStateAnimator::ANIMATION_FADE_OUT,
                                        speed);
   }
 }
 
 }  // namespace ash