cc: Define ScrollOffsetAnimationCurve

This defines ScrollOffsetAnimationCurve, which will be used
by the implementation of the CSSOM View smooth scroll API.

BUG=243871

Review URL: https://codereview.chromium.org/60113007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237121 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 5 insertions, 1 deletions

diff --git a/cc/animation/animation_curve.h b/cc/animation/animation_curve.h
index f84bb1a..9bcccba 100644
--- a/cc/animation/animation_curve.h
+++ b/cc/animation/animation_curve.h
@@ -19,13 +19,14 @@ namespace cc {
 class ColorAnimationCurve;
 class FilterAnimationCurve;
 class FloatAnimationCurve;
+class ScrollOffsetAnimationCurve;
 class TransformAnimationCurve;
 class TransformOperations;
 
 // An animation curve is a function that returns a value given a time.
 class CC_EXPORT AnimationCurve {
  public:
-  enum CurveType { Color, Float, Transform, Filter };
+  enum CurveType { Color, Float, Transform, Filter, ScrollOffset };
 
   virtual ~AnimationCurve() {}
 
@@ -37,6 +38,9 @@ class CC_EXPORT AnimationCurve {
   const FloatAnimationCurve* ToFloatAnimationCurve() const;
   const TransformAnimationCurve* ToTransformAnimationCurve() const;
   const FilterAnimationCurve* ToFilterAnimationCurve() const;
+  const ScrollOffsetAnimationCurve* ToScrollOffsetAnimationCurve() const;
+
+  ScrollOffsetAnimationCurve* ToScrollOffsetAnimationCurve();
 };
 
 class CC_EXPORT ColorAnimationCurve : public AnimationCurve {