NOT FOR REVIEW - convert to cc animation

ui/gfx/animation/tween.cc

 // Copyright (c) 2012 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 "ui/gfx/animation/tween.h"
 
 #include <math.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 185 matching lines @@
     return end_transform;
   if (value <= 0.0)
     return start_transform;
 
   gfx::Transform to_return = end_transform;
   to_return.Blend(start_transform, value);
 
   return to_return;
 }
 
+gfx::SizeF Tween::SizeValueBetween(double value,
+                                   const gfx::SizeF& start_size,
+                                   const gfx::SizeF& target_size) {
+  return gfx::SizeF(
+      Tween::FloatValueBetween(value, start_size.width(), target_size.width()),
+      Tween::FloatValueBetween(value, start_size.height(),
+                               target_size.height()));
+}
+
 }  // namespace gfx