CSSValue Immediates: Replace CSSValue usage with const references

Source/core/css/parser/CSSPropertyParser.cpp

Index: Source/core/css/parser/CSSPropertyParser.cpp
diff --git a/Source/core/css/parser/CSSPropertyParser.cpp b/Source/core/css/parser/CSSPropertyParser.cpp
index f4b04463235b9b7fac2cead8fdc56c6832f60cd0..4d2b62844314c6630ae1cd12d6106d6cb139cfb1 100644
--- a/Source/core/css/parser/CSSPropertyParser.cpp
+++ b/Source/core/css/parser/CSSPropertyParser.cpp
@@ -405,7 +405,7 @@ void CSSPropertyParser::addExpandedPropertyForValue(CSSPropertyID propId, CSSVal
         return;
     }
 
-    CSSValue value = prpValue;
+    const CSSValue& value = prpValue;
     ShorthandScope scope(this, propId);
     const CSSPropertyID* longhands = shorthand.properties();
     for (unsigned i = 0; i < shorthandLength; ++i)
@@ -3351,7 +3351,7 @@ NullableCSSValue CSSPropertyParser::parseGridPosition()
     return values.release();
 }
 
-static CSSValue gridMissingGridPositionValue(CSSValue value)
+static CSSValue gridMissingGridPositionValue(const CSSValue& value)
 {
     if (value.isPrimitiveValue() && toCSSPrimitiveValue(value).isCustomIdent())
         return value;
@@ -3403,7 +3403,7 @@ bool CSSPropertyParser::parseGridTemplateRowsAndAreas(NullableCSSValue templateC
 
     while (m_valueList->current()) {
         // Handle leading <custom-ident>*.
-        if (!parseGridLineNames(*m_valueList, *templateRows, trailingIdentWasAdded ? toCSSGridLineNamesValue(NullableCSSValue(templateRows->item(templateRows->length() - 1))) : nullptr))
+        if (!parseGridLineNames(*m_valueList, *templateRows, trailingIdentWasAdded ? NullableCSSValue(toCSSGridLineNamesValue(templateRows->item(templateRows->length() - 1))) : nullptr))
             return false;
 
         // Handle a template-area's row.
@@ -5490,7 +5490,7 @@ public:
     bool allowWidth() const { return m_allowWidth; }
     bool requireOutset() const { return m_requireOutset; }
 
-    void commitImage(CSSValue image)
+    void commitImage(const CSSValue& image)
     {
         m_image = image;
         m_canAdvance = true;
@@ -5555,7 +5555,7 @@ public:
         m_allowImage = !m_image;
         m_allowRepeat = !m_repeat;
     }
-    void commitRepeat(CSSValue repeat)
+    void commitRepeat(const CSSValue& repeat)
     {
         m_repeat = repeat;
         m_canAdvance = true;
@@ -6842,7 +6842,7 @@ NullableCSSValue CSSPropertyParser::parseImageSet(CSSParserValueList* valueList)
         if (arg->unit != CSSPrimitiveValue::CSS_URI)
             return nullptr;
 
-        CSSValue image = createCSSImageValueWithReferrer(arg->string, completeURL(arg->string));
+        const CSSValue& image = createCSSImageValueWithReferrer(arg->string, completeURL(arg->string));
         imageSet->append(image);
 
         arg = functionArgs->next();