Do not zero-initialize RawPtr.

Source/core/css/CSSGradientValue.cpp

 /*
  * Copyright (C) 2008 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 104 matching lines @@
 PassRefPtrWillBeRawPtr<CSSGradientValue> CSSGradientValue::gradientWithStylesResolved(const TextLinkColors& textLinkColors, Color currentColor)
 {
     bool derived = false;
     for (unsigned i = 0; i < m_stops.size(); i++)
         if (m_stops[i].m_color->colorIsDerivedFromElement()) {
             m_stops[i].m_colorIsDerivedFromElement = true;
             derived = true;
             break;
         }
 
-    RefPtrWillBeRawPtr<CSSGradientValue> result;
+    RefPtrWillBeRawPtr<CSSGradientValue> result = nullptr;
     if (!derived)
         result = this;
     else if (isLinearGradientValue())
         result = toCSSLinearGradientValue(this)->clone();
     else if (isRadialGradientValue())
         result = toCSSRadialGradientValue(this)->clone();
     else {
         ASSERT_NOT_REACHED();
         return nullptr;
     }
@@ skipping 1047 matching lines @@
     visitor->trace(m_firstRadius);
     visitor->trace(m_secondRadius);
     visitor->trace(m_shape);
     visitor->trace(m_sizingBehavior);
     visitor->trace(m_endHorizontalSize);
     visitor->trace(m_endVerticalSize);
     CSSGradientValue::traceAfterDispatch(visitor);
 }
 
 } // namespace WebCore