Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/animation/css/CSSAnimatableValueFactory.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 66 matching lines @@
     case MaxContent:
     case FillAvailable:
     case FitContent:
         return AnimatableUnknown::create(CSSPrimitiveValue::create(length));
     case Undefined:
         return AnimatableUnknown::create(CSSValueNone);
     case ExtendToZoom: // Does not apply to elements.
     case DeviceWidth:
     case DeviceHeight:
         ASSERT_NOT_REACHED();
-        return 0;
+        return nullptr;
     }
     ASSERT_NOT_REACHED();
-    return 0;
+    return nullptr;
 }
 
 static PassRefPtr<AnimatableValue> createFromLineHeight(const Length& length, const RenderStyle& style)
 {
     if (length.type() == Percent) {
         double value = length.value();
         // -100% is used to represent "normal" line height.
         if (value == -100)
             return AnimatableUnknown::create(CSSValueNormal);
         return AnimatableDouble::create(value);
@@ skipping 63 matching lines @@
 {
     switch (fillSize.type) {
     case SizeLength:
         return createFromLengthSize(fillSize.size, style);
     case Contain:
     case Cover:
     case SizeNone:
         return AnimatableUnknown::create(CSSPrimitiveValue::create(fillSize.type));
     default:
         ASSERT_NOT_REACHED();
-        return 0;
+        return nullptr;
     }
 }
 
 inline static PassRefPtr<AnimatableValue> createFromBackgroundPosition(const Length& length, bool originIsSet, BackgroundEdgeOrigin origin, const RenderStyle& style)
 {
     if (!originIsSet || origin == LeftEdge || origin == TopEdge)
         return createFromLength(length, style);
 
     return AnimatableLength::create(CSSCalcValue::createExpressionNode(
         CSSCalcValue::createExpressionNode(CSSPrimitiveValue::create(100, CSSPrimitiveValue::CSS_PERCENTAGE), true),
@@ skipping 270 matching lines @@
         return createFromDouble(style.wordSpacing());
     case CSSPropertyVisibility:
         return AnimatableVisibility::create(style.visibility());
     case CSSPropertyZIndex:
         return createFromDouble(style.zIndex());
     case CSSPropertyZoom:
         return createFromDouble(style.zoom());
     default:
         ASSERT_NOT_REACHED();
         // This return value is to avoid a release crash if possible.
-        return AnimatableUnknown::create(0);
+        return AnimatableUnknown::create(nullptr);
     }
 }
 
 } // namespace WebCore