Oilpan: fix build after r202625.

Source/core/css/CSSCrossfadeValue.cpp

Index: Source/core/css/CSSCrossfadeValue.cpp
diff --git a/Source/core/css/CSSCrossfadeValue.cpp b/Source/core/css/CSSCrossfadeValue.cpp
index 41af71c2e596c4daec771cb67e63b6b9bfbf1805..3816da275d85beed59a326de84d2c65d68a6f2c5 100644
--- a/Source/core/css/CSSCrossfadeValue.cpp
+++ b/Source/core/css/CSSCrossfadeValue.cpp
@@ -119,8 +119,12 @@ String CSSCrossfadeValue::customCSSText() const
 
 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;
+    RefPtrWillBeRawPtr<CSSValue> fromValue = m_fromValue;
+    if (m_fromValue->isImageValue())
+        fromValue = toCSSImageValue(*m_fromValue).valueWithURLMadeAbsolute();
+    RefPtrWillBeRawPtr<CSSValue> toValue = m_toValue;
+    if (m_toValue->isImageValue())
+        toValue = toCSSImageValue(*m_toValue).valueWithURLMadeAbsolute();
     return CSSCrossfadeValue::create(fromValue.release(), toValue.release(), m_percentageValue);
 }