Add support for bounds animations

cc/animation/animation_curve.cc

 // Copyright 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 "cc/animation/animation_curve.h"
 
 #include "base/logging.h"
 #include "cc/animation/scroll_offset_animation_curve.h"
 
 namespace cc {
@@ skipping 39 matching lines @@
     const {
   DCHECK(Type() == AnimationCurve::SCROLL_OFFSET);
   return static_cast<const ScrollOffsetAnimationCurve*>(this);
 }
 
 ScrollOffsetAnimationCurve* AnimationCurve::ToScrollOffsetAnimationCurve() {
   DCHECK(Type() == AnimationCurve::SCROLL_OFFSET);
   return static_cast<ScrollOffsetAnimationCurve*>(this);
 }
 
+const SizeAnimationCurve* AnimationCurve::ToSizeAnimationCurve() const {
+  DCHECK(Type() == AnimationCurve::SIZE);
+  return static_cast<const SizeAnimationCurve*>(this);
+}
+
+AnimationCurve::CurveType SizeAnimationCurve::Type() const {
+  return SIZE;
+}
+
 }  // namespace cc