CC: Stop TimingFunction inheriting from AnimationCurve.

cc/animation/timing_function.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 "base/logging.h"
 #include "cc/animation/timing_function.h"
 
 namespace cc {
 
 TimingFunction::TimingFunction() {}
 
 TimingFunction::~TimingFunction() {}
 
-double TimingFunction::Duration() const {
-  return 1.0;
-}
-
 scoped_ptr<CubicBezierTimingFunction> CubicBezierTimingFunction::Create(
     double x1, double y1, double x2, double y2) {
   return make_scoped_ptr(new CubicBezierTimingFunction(x1, y1, x2, y2));
 }
 
 CubicBezierTimingFunction::CubicBezierTimingFunction(double x1,
                                                      double y1,
                                                      double x2,
                                                      double y2)
     : bezier_(x1, y1, x2, y2) {}
 
 CubicBezierTimingFunction::~CubicBezierTimingFunction() {}
 
 float CubicBezierTimingFunction::GetValue(double x) const {
   return static_cast<float>(bezier_.Solve(x));
 }
 
-scoped_ptr<AnimationCurve> CubicBezierTimingFunction::Clone() const {
-  return make_scoped_ptr(
-      new CubicBezierTimingFunction(*this)).PassAs<AnimationCurve>();
+scoped_ptr<TimingFunction> CubicBezierTimingFunction::Clone() const {
+  return make_scoped_ptr(new CubicBezierTimingFunction(*this))
+      .PassAs<TimingFunction>();
 }
 
 void CubicBezierTimingFunction::Range(float* min, float* max) const {
   double min_d = 0;
   double max_d = 1;
   bezier_.Range(&min_d, &max_d);
   *min = static_cast<float>(min_d);
   *max = static_cast<float>(max_d);
 }
 
@@ skipping 17 matching lines @@
   return CubicBezierTimingFunction::Create(
       0.0, 0.0, 0.58, 1.0).PassAs<TimingFunction>();
 }
 
 scoped_ptr<TimingFunction> EaseInOutTimingFunction::Create() {
   return CubicBezierTimingFunction::Create(
       0.42, 0.0, 0.58, 1).PassAs<TimingFunction>();
 }
 
 }  // namespace cc