BackgroundImage incorrectly returns empty url() when created on-the-fly

Source/core/css/CSSCrossfadeValue.cpp

 /*
  * Copyright (C) 2011 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 99 matching lines @@
     result.appendLiteral("-webkit-cross-fade(");
     result.append(m_fromValue->cssText());
     result.appendLiteral(", ");
     result.append(m_toValue->cssText());
     result.appendLiteral(", ");
     result.append(m_percentageValue->cssText());
     result.append(')');
     return result.toString();
 }
 
+PassRefPtrWillBeRawPtr<CSSCrossfadeValue> CSSCrossfadeValue::valueWithURLsMadeAbsolute()
+{
+    RefPtrWillBeRawPtr<CSSValue> fromValue = m_fromValue->isImageValue() ? toCSSImageValue(*m_fromValue).valueWithURLMadeAbsolute() : m_fromValue;
+    RefPtrWillBeRawPtr<CSSValue> toValue = m_toValue->isImageValue() ? toCSSImageValue(*m_toValue).valueWithURLMadeAbsolute() : m_toValue;
+    return CSSCrossfadeValue::create(fromValue.release(), toValue.release(), m_percentageValue);
+}
+
 IntSize CSSCrossfadeValue::fixedSize(const LayoutObject* layoutObject)
 {
     Image* fromImage = renderableImageForCSSValue(m_fromValue.get(), layoutObject);
     Image* toImage = renderableImageForCSSValue(m_toValue.get(), layoutObject);
 
     if (!fromImage || !toImage)
         return IntSize();
 
     IntSize fromImageSize = fromImage->size();
     IntSize toImageSize = toImage->size();
@@ skipping 94 matching lines @@
 DEFINE_TRACE_AFTER_DISPATCH(CSSCrossfadeValue)
 {
     visitor->trace(m_fromValue);
     visitor->trace(m_toValue);
     visitor->trace(m_percentageValue);
     visitor->trace(m_crossfadeSubimageObserver);
     CSSImageGeneratorValue::traceAfterDispatch(visitor);
 }
 
 } // namespace blink