Web Animations: Clip animation active intervals if endDelay is negative

third_party/WebKit/Source/core/animation/KeyframeEffect.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 214 matching lines @@
         return;
     ASSERT(animation());
     if (isInEffect() && !animation()->effectSuppressed())
         const_cast<KeyframeEffect*>(this)->applyEffects();
     else if (m_sampledEffect)
         const_cast<KeyframeEffect*>(this)->clearEffects();
 }
 
 double KeyframeEffect::calculateTimeToEffectChange(bool forwards, double localTime, double timeToNextIteration) const
 {
-    const double start = specifiedTiming().startDelay;
-    const double end = start + activeDurationInternal();
+    const double startTime = specifiedTiming().startDelay;
+    const double endTimeMinusEndDelay = startTime + activeDurationInternal();
+    const double endTime = endTimeMinusEndDelay + specifiedTiming().endDelay;
+    const double afterTime = std::min(endTimeMinusEndDelay, endTime);
 
     switch (getPhase()) {
     case PhaseNone:
         return std::numeric_limits<double>::infinity();
     case PhaseBefore:
-        ASSERT(start >= localTime);
+        ASSERT(startTime >= localTime);
         return forwards
-            ? start - localTime
+            ? startTime - localTime
             : std::numeric_limits<double>::infinity();
     case PhaseActive:
         if (forwards) {
             // Need service to apply fill / fire events.
-            const double timeToEnd = end - localTime;
+            const double timeToEnd = afterTime - localTime;
             if (requiresIterationEvents()) {
                 return std::min(timeToEnd, timeToNextIteration);
             }
             return timeToEnd;
         }
         return 0;
     case PhaseAfter:
-        ASSERT(localTime >= end);
+        ASSERT(localTime >= afterTime);
         // If this KeyframeEffect is still in effect then it will need to update
         // when its parent goes out of effect. We have no way of knowing when
         // that will be, however, so the parent will need to supply it.
         return forwards
             ? std::numeric_limits<double>::infinity()
-            : localTime - end;
+            : localTime - afterTime;
     default:
         ASSERT_NOT_REACHED();
         return std::numeric_limits<double>::infinity();
     }
 }
 
 void KeyframeEffect::notifySampledEffectRemovedFromAnimationStack()
 {
     m_sampledEffect = nullptr;
 }
@@ skipping 95 matching lines @@
 
 DEFINE_TRACE(KeyframeEffect)
 {
     visitor->trace(m_target);
     visitor->trace(m_model);
     visitor->trace(m_sampledEffect);
     AnimationEffect::trace(visitor);
 }
 
 } // namespace blink