Simplify animation/transition parsing slightly

Source/core/animation/EffectInput.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 81 matching lines @@
 
         keyframes.append(keyframe);
 
         String compositeString;
         keyframeDictionaryVector[i].get("composite", compositeString);
         if (compositeString == "add")
             keyframe->setComposite(AnimationEffect::CompositeAdd);
 
         String timingFunctionString;
         if (keyframeDictionaryVector[i].get("easing", timingFunctionString)) {
-            RefPtrWillBeRawPtr<CSSValue> timingFunctionValue = BisonCSSParser::parseAnimationTimingFunctionValue(timingFunctionString);
-            if (timingFunctionValue)
+            if (RefPtrWillBeRawPtr<CSSValue> timingFunctionValue = BisonCSSParser::parseAnimationTimingFunctionValue(timingFunctionString))
                 keyframe->setEasing(CSSToStyleMap::mapAnimationTimingFunction(timingFunctionValue.get(), true));
         }
 
         Vector<String> keyframeProperties;
         keyframeDictionaryVector[i].getOwnPropertyNames(keyframeProperties);
         for (size_t j = 0; j < keyframeProperties.size(); ++j) {
             String property = keyframeProperties[j];
             CSSPropertyID id = camelCaseCSSPropertyNameToID(property);
             if (id == CSSPropertyInvalid)
                 continue;
@@ skipping 15 matching lines @@
     if (!keyframeEffectModel->isReplaceOnly()) {
         exceptionState.throwDOMException(NotSupportedError, "Partial keyframes are not supported.");
         return nullptr;
     }
     keyframeEffectModel->forceConversionsToAnimatableValues(element);
 
     return keyframeEffectModel;
 }
 
 } // namespace WebCore