CSSValue Immediates: Make CSSPrimitiveValue a container

Source/core/css/resolver/StyleBuilderConverter.h

Index: Source/core/css/resolver/StyleBuilderConverter.h
diff --git a/Source/core/css/resolver/StyleBuilderConverter.h b/Source/core/css/resolver/StyleBuilderConverter.h
index 3290207939e3df0becf9c77b44fbddc7a4460475..f7cbc9dba693ab0f9d572f7deadc397deee03984 100644
--- a/Source/core/css/resolver/StyleBuilderConverter.h
+++ b/Source/core/css/resolver/StyleBuilderConverter.h
@@ -125,7 +125,7 @@ T StyleBuilderConverter::convertFlags(StyleResolverState& state, CSSValue value)
 template <typename T>
 T StyleBuilderConverter::convertLineWidth(StyleResolverState& state, CSSValue value)
 {
-    CSSPrimitiveValue& primitiveValue = toCSSPrimitiveValue(value);
+    CSSPrimitiveValue primitiveValue = toCSSPrimitiveValue(value);
     CSSValueID valueID = primitiveValue.getValueID();
     if (valueID == CSSValueThin)
         return 1;
@@ -151,7 +151,7 @@ T StyleBuilderConverter::convertLineWidth(StyleResolverState& state, CSSValue va
 template <CSSValueID IdForNone>
 AtomicString StyleBuilderConverter::convertString(StyleResolverState&, CSSValue value)
 {
-    CSSPrimitiveValue& primitiveValue = toCSSPrimitiveValue(value);
+    CSSPrimitiveValue primitiveValue = toCSSPrimitiveValue(value);
     if (primitiveValue.getValueID() == IdForNone)
         return nullAtom;
     return AtomicString(primitiveValue.getStringValue());