Enable hide animation for login screen.

chrome/browser/chromeos/login/lock_window_aura.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 "chrome/browser/chromeos/login/lock_window_aura.h"
 
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
+#include "ash/wm/window_animations.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
 
 namespace chromeos {
 
 LockWindow* LockWindow::Create() {
   return new LockWindowAura();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ skipping 21 matching lines @@
 void LockWindowAura::Init() {
   views::Widget::InitParams params(
       views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
   params.bounds = gfx::Rect(aura::RootWindow::GetInstance()->GetHostSize());
   views::Widget::Init(params);
   // TODO(flackr): Use a property to specify this container rather than
   // depending on shell implementation.
   ash::Shell::GetInstance()->GetContainer(
       ash::internal::kShellWindowId_LockScreenContainer)->
       AddChild(GetNativeView());
+  ash::SetWindowVisibilityAnimationTransition(GetNativeView(),
+                                              ash::ANIMATE_NONE);
 }
 
 }  // namespace chromeos