Do not zero-initialize RawPtr.

Source/core/animation/css/CSSAnimations.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 500 matching lines @@
         element->document().cssPendingAnimations().add(player.get());
         runningTransition.transition = transition.get();
         m_transitions.set(id, runningTransition);
         ASSERT(id != CSSPropertyInvalid);
         blink::Platform::current()->histogramSparse("WebCore.Animation.CSSProperties", UseCounter::mapCSSPropertyIdToCSSSampleIdForHistogram(id));
     }
 }
 
 void CSSAnimations::calculateTransitionUpdateForProperty(CSSPropertyID id, const CSSAnimationData* anim, const RenderStyle& oldStyle, const RenderStyle& style, const TransitionMap* activeTransitions, CSSAnimationUpdate* update, const Element* element)
 {
-    RefPtrWillBeRawPtr<AnimatableValue> to;
+    RefPtrWillBeRawPtr<AnimatableValue> to = nullptr;
     if (activeTransitions) {
         TransitionMap::const_iterator activeTransitionIter = activeTransitions->find(id);
         if (activeTransitionIter != activeTransitions->end()) {
             to = CSSAnimatableValueFactory::create(id, style);
             const AnimatableValue* activeTo = activeTransitionIter->value.to;
             if (to->equals(activeTo))
                 return;
             update->cancelTransition(id);
             ASSERT(!element->activeAnimations() || !element->activeAnimations()->isAnimationStyleChange());
         }
@@ skipping 358 matching lines @@
             CSSPropertyID id = convertToCSSPropertyID(i);
             if (isAnimatableProperty(id))
                 properties.append(id);
         }
         propertyShorthand = StylePropertyShorthand(CSSPropertyInvalid, properties.begin(), properties.size());
     }
     return propertyShorthand;
 }
 
 } // namespace WebCore