Web Animations API: Deferred computation of interpolated values

Source/core/animation/CompositorAnimations.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 125 matching lines @@
     PropertySet properties = keyframeEffect.properties();
 
     if (properties.isEmpty())
         return false;
 
     for (PropertySet::const_iterator it = properties.begin(); it != properties.end(); ++it) {
         const PropertySpecificKeyframeVector& frames = keyframeEffect.getPropertySpecificKeyframes(*it);
         ASSERT(frames.size() >= 2);
         for (size_t i = 0; i < frames.size(); ++i) {
             const Keyframe::PropertySpecificKeyframe *frame = frames[i].get();
-            if (frame->composite() != AnimationEffect::CompositeReplace)
+            // FIXME: Determine candidacy based on the CSSValue instead of a snapshot AnimatableValue.
+            if (frame->composite() != AnimationEffect::CompositeReplace || !frame->getAnimatableValue())
                 return false;
 
             switch (*it) {
             case CSSPropertyOpacity:
                 break;
             case CSSPropertyTransform:
                 if (toAnimatableTransform(frame->getAnimatableValue().get())->transformOperations().dependsOnBoxSize())
                     return false;
                 break;
             case CSSPropertyWebkitFilter: {
@@ skipping 299 matching lines @@
         animation->setIterations(compositorTiming.adjustedIterationCount);
         animation->setTimeOffset(compositorTiming.scaledTimeOffset);
         animation->setAlternatesDirection(compositorTiming.alternate);
 
         animations.append(animation.release());
     }
     ASSERT(!animations.isEmpty());
 }
 
 } // namespace WebCore