Do not zero-initialize RawPtr.

Source/core/animation/CompositorAnimationsTest.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 132 matching lines @@
         RefPtrWillBeRawPtr<Keyframe> keyframe = Keyframe::create();
         keyframe->setPropertyValue(id, value);
         keyframe->setComposite(AnimationEffect::CompositeReplace);
         keyframe->setOffset(offset);
         keyframe->setEasing(LinearTimingFunction::preset());
         return keyframe;
     }
 
     PassRefPtrWillBeRawPtr<Keyframe> createDefaultKeyframe(CSSPropertyID id, AnimationEffect::CompositeOperation op, double offset = 0)
     {
-        RefPtrWillBeRawPtr<AnimatableValue> value;
+        RefPtrWillBeRawPtr<AnimatableValue> value = nullptr;
         if (id == CSSPropertyWebkitTransform)
             value = AnimatableTransform::create(TransformOperations());
         else
             value = AnimatableDouble::create(10.0);
 
         RefPtrWillBeRawPtr<Keyframe> keyframe = createReplaceOpKeyframe(id, value.get(), offset);
         keyframe->setComposite(op);
         return keyframe;
     }
 
@@ skipping 36 matching lines @@
         if (d) {
             frames.append(d);
             EXPECT_LE(c->offset(), d->offset());
             EXPECT_EQ(d->offset(), 1.0);
         } else {
             EXPECT_EQ(to->offset(), 1.0);
         }
         if (!HasFatalFailure()) {
             return KeyframeEffectModel::create(frames);
         }
-        return PassRefPtrWillBeRawPtr<KeyframeEffectModel>();
+        return nullptr;
     }
 
 };
 
 // -----------------------------------------------------------------------
 // -----------------------------------------------------------------------
 
 TEST_F(AnimationCompositorAnimationsTest, isCandidateForAnimationOnCompositorKeyframeMultipleCSSProperties)
 {
     RefPtrWillBeRawPtr<Keyframe> keyframeGoodMultiple = createDefaultKeyframe(CSSPropertyOpacity, AnimationEffect::CompositeReplace);
@@ skipping 679 matching lines @@
     // Go!
     setCompositorForTesting(mockCompositor);
     Vector<OwnPtr<blink::WebAnimation> > result;
     getAnimationOnCompositor(m_timing, *effect.get(), result);
     EXPECT_EQ(1U, result.size());
     result[0].clear();
 }
 
 
 } // namespace WebCore