Move animation code to new ui/base/animation directory....

ui/base/animation/tween.h

Index: ui/base/animation/tween.h
===================================================================
--- ui/base/animation/tween.h	(revision 0)
+++ ui/base/animation/tween.h	(working copy)
@@ -1,9 +1,9 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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.
 
-#ifndef APP_TWEEN_H_
-#define APP_TWEEN_H_
+#ifndef UI_BASE_ANIMATION_TWEEN_H_
+#define UI_BASE_ANIMATION_TWEEN_H_
 #pragma once
 
 #include "base/basictypes.h"
@@ -12,6 +12,8 @@
 class Rect;
 }
 
+namespace ui {
+
 class Tween {
  public:
   enum Type {
@@ -41,4 +43,6 @@
   DISALLOW_COPY_AND_ASSIGN(Tween);
 };
 
-#endif  // APP_TWEEN_H_
+}  // namespace ui
+
+#endif  // UI_BASE_ANIMATION_TWEEN_H_