Web animations: Supply CSS transition easing

Source/core/animation/InterpolationEffect.cpp

 // Copyright 2014 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 "config.h"
 #include "core/animation/InterpolationEffect.h"
 
 namespace WebCore {
 
-namespace {
-    const double accuracyForKeyframeEasing = 0.0000001;
-}
-
-PassOwnPtr<Vector<RefPtr<Interpolation> > > InterpolationEffect::getActiveInterpolations(double fraction) const
+PassOwnPtr<Vector<RefPtr<Interpolation> > > InterpolationEffect::getActiveInterpolations(double fraction, double iterationDuration) const
 {
 
     Vector<RefPtr<Interpolation> >* result = new Vector<RefPtr<Interpolation> >();
 
     for (size_t i = 0; i < m_interpolations.size(); ++i) {
         const InterpolationRecord* record = m_interpolations[i].get();
         if (fraction >= record->m_applyFrom && fraction < record->m_applyTo) {
             RefPtr<Interpolation> interpolation = record->m_interpolation;
             double localFraction = (fraction - record->m_start) / (record->m_end - record->m_start);
             if (record->m_easing)
-                localFraction = record->m_easing->evaluate(localFraction, accuracyForKeyframeEasing);
+                localFraction = record->m_easing->evaluate(localFraction, accuracyForDuration(iterationDuration));
             interpolation->interpolate(0, localFraction);
             result->append(interpolation);
         }
     }
 
     return adoptPtr(result);
 }
 
 }