Scroll offset animation curve retargeting.

cc/animation/timing_function.h

 // 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.
 
 #ifndef CC_ANIMATION_TIMING_FUNCTION_H_
 #define CC_ANIMATION_TIMING_FUNCTION_H_
 
 #include "cc/animation/animation_curve.h"
 #include "cc/base/cc_export.h"
 #include "ui/gfx/geometry/cubic_bezier.h"
 
 namespace cc {
 
 // See http://www.w3.org/TR/css3-transitions/.
 class CC_EXPORT TimingFunction : public FloatAnimationCurve {
  public:
   virtual ~TimingFunction();
 
   // Partial implementation of FloatAnimationCurve.
   virtual double Duration() const OVERRIDE;
 
   // The smallest and largest values returned by GetValue for inputs in
   // [0, 1].
   virtual void Range(float* min, float* max) const = 0;
+  virtual float Velocity(double time) const = 0;
 
  protected:
   TimingFunction();
 
  private:
   DISALLOW_ASSIGN(TimingFunction);
 };
 
 class CC_EXPORT CubicBezierTimingFunction : public TimingFunction {
  public:
   static scoped_ptr<CubicBezierTimingFunction> Create(double x1, double y1,
                                                       double x2, double y2);
   virtual ~CubicBezierTimingFunction();
 
   // Partial implementation of FloatAnimationCurve.
   virtual float GetValue(double time) const OVERRIDE;
   virtual scoped_ptr<AnimationCurve> Clone() const OVERRIDE;
 
   virtual void Range(float* min, float* max) const OVERRIDE;
+  virtual float Velocity(double time) const OVERRIDE;
 
  protected:
   CubicBezierTimingFunction(double x1, double y1, double x2, double y2);
 
   gfx::CubicBezier bezier_;
 
  private:
   DISALLOW_ASSIGN(CubicBezierTimingFunction);
 };
 
@@ skipping 25 matching lines @@
  public:
   static scoped_ptr<TimingFunction> Create();
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(EaseInOutTimingFunction);
 };
 
 }  // namespace cc
 
 #endif  // CC_ANIMATION_TIMING_FUNCTION_H_