Fix crash in keyframe-effect/getComputedTiming tests

third_party/WebKit/Source/core/animation/AnimationEffect.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 140 matching lines @@
 
         double currentIteration;
         double timeFraction;
         if (const double iterationDuration = this->iterationDuration()) {
             const double startOffset = multiplyZeroAlwaysGivesZero(m_timing.iterationStart, iterationDuration);
             ASSERT(startOffset >= 0);
             const double scaledActiveTime = calculateScaledActiveTime(activeDuration, activeTime, startOffset, m_timing);
             const double iterationTime = calculateIterationTime(iterationDuration, repeatedDuration(), scaledActiveTime, startOffset, m_timing);
 
             currentIteration = calculateCurrentIteration(iterationDuration, iterationTime, scaledActiveTime, m_timing);
-            timeFraction = calculateTransformedTime(currentIteration, iterationDuration, iterationTime, m_timing) / iterationDuration;
+            const double transformedTime = calculateTransformedTime(currentIteration, iterationDuration, iterationTime, m_timing);
+            if (!std::isfinite(iterationDuration))

[alancutter (OOO until 2018), 2016/04/15 01:01:59]

Is there a spec bug we can link to given that this a work around a problem with
the spec?

+                timeFraction = fmod(m_timing.iterationStart, 1.0);
+            else
+                timeFraction = transformedTime / iterationDuration;
 
             if (!isNull(iterationTime)) {
                 timeToNextIteration = (iterationDuration - iterationTime) / std::abs(m_timing.playbackRate);
                 if (activeDuration - activeTime < timeToNextIteration)
                     timeToNextIteration = std::numeric_limits<double>::infinity();
             }
         } else {
             const double localIterationDuration = 1;
             const double localRepeatedDuration = localIterationDuration * m_timing.iterationCount;
             ASSERT(localRepeatedDuration >= 0);
@@ skipping 51 matching lines @@
     return AnimationEffectTiming::create(this);
 }
 
 DEFINE_TRACE(AnimationEffect)
 {
     visitor->trace(m_animation);
     visitor->trace(m_eventDelegate);
 }
 
 } // namespace blink