appp: Remove tween.h header file.

It seems this file was left when all the other animation files were moved
to ui/base/animation/.

BUG=None
TEST=trybots

Review URL: http://codereview.chromium.org/6376010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@72432 0039d316-1c4b-4281-b951-d872f2087c98

app/tween.h

-// Copyright (c) 2010 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_
-#pragma once
-
-#include "base/basictypes.h"
-
-namespace gfx {
-class Rect;
-}
-
-class Tween {
- public:
-  enum Type {
-    LINEAR,        // Linear.
-    EASE_OUT,      // Fast in, slow out (default).
-    EASE_IN,       // Slow in, fast out.
-    EASE_IN_OUT,   // Slow in and out, fast in the middle.
-    FAST_IN_OUT,   // Fast in and out, slow in the middle.
-    EASE_OUT_SNAP, // Fast in, slow out, snap to final value.
-    ZERO,          // Returns a value of 0 always.
-  };
-
-  // Returns the value based on the tween type. |state| is from 0-1.
-  static double CalculateValue(Type type, double state);
-
-  // Conveniences for getting a value between a start and end point.
-  static double ValueBetween(double value, double start, double target);
-  static int ValueBetween(double value, int start, int target);
-  static gfx::Rect ValueBetween(double value,
-                                const gfx::Rect& start_bounds,
-                                const gfx::Rect& target_bounds);
-
- private:
-  Tween();
-  ~Tween();
-
-  DISALLOW_COPY_AND_ASSIGN(Tween);
-};
-
-#endif  // APP_TWEEN_H_