CSSValue Immediates: Replace CSSPrimitiveValue 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 113724f4d307a3fba6222cdf0442e502f3397cf4..604179f100eedc06dbfaf8c1c2bf254ac076fa47 100644
--- a/Source/core/css/parser/CSSPropertyParser.cpp
+++ b/Source/core/css/parser/CSSPropertyParser.cpp
@@ -75,7 +75,7 @@ static bool equalIgnoringCase(const CSSParserString& a, const char (&b)[N])
     return a.is8Bit() ? WTF::equalIgnoringCase(b, a.characters8(), length) : WTF::equalIgnoringCase(b, a.characters16(), length);
 }
 
-static CSSPrimitiveValue createPrimitiveValuePair(CSSPrimitiveValue first, CSSPrimitiveValue second, Pair::IdenticalValuesPolicy identicalValuesPolicy = Pair::DropIdenticalValues)
+static CSSPrimitiveValue createPrimitiveValuePair(const CSSPrimitiveValue& first, const CSSPrimitiveValue& second, Pair::IdenticalValuesPolicy identicalValuesPolicy = Pair::DropIdenticalValues)
 {
     return cssValuePool().createValue(Pair::create(first, second, identicalValuesPolicy));
 }
@@ -122,7 +122,7 @@ bool CSSPropertyParser::parseValue(CSSPropertyID unresolvedProperty, bool import
     return parseSuccess;
 }
 
-void CSSPropertyParser::addProperty(CSSPropertyID propId, CSSValue value, bool important, bool implicit)
+void CSSPropertyParser::addProperty(CSSPropertyID propId, const CSSValue& value, bool important, bool implicit)
 {
     ASSERT(!isPropertyAlias(propId));
 
@@ -519,7 +519,7 @@ bool CSSPropertyParser::parseValue(CSSPropertyID unresolvedProperty, bool import
             ShorthandScope scope(this, CSSPropertyBorderSpacing);
             if (!parseValue(CSSPropertyWebkitBorderHorizontalSpacing, important))
                 return false;
-            CSSValue value = m_parsedProperties.last().value();
+            const CSSValue& value = m_parsedProperties.last().value();
             addProperty(CSSPropertyWebkitBorderVerticalSpacing, value, important);
             return true;
         }
@@ -1561,7 +1561,7 @@ bool CSSPropertyParser::parseValue(CSSPropertyID unresolvedProperty, bool import
     return false;
 }
 
-void CSSPropertyParser::addFillValue(NullableCSSValue& lval, CSSValue rval)
+void CSSPropertyParser::addFillValue(NullableCSSValue& lval, const CSSValue& rval)
 {
     if (lval) {
         if (lval->isBaseValueList())
@@ -1750,7 +1750,7 @@ static bool isValidTransitionPropertyList(CSSValueList* value)
         // FIXME: Shorthand parsing shouldn't add initial to the list since it won't round-trip
         if (property.isInitialValue())
             continue;
-        CSSPrimitiveValue primitiveValue = toCSSPrimitiveValue(property);
+        const CSSPrimitiveValue& primitiveValue = toCSSPrimitiveValue(property);
         if (primitiveValue.isValueID() && primitiveValue.getValueID() == CSSValueNone)
             return false;
     }
@@ -2016,7 +2016,7 @@ bool CSSPropertyParser::parse4Values(CSSPropertyID propId, const CSSPropertyID *
         case 1: {
             if (!parseValue(properties[0], important))
                 return false;
-            CSSValue value = m_parsedProperties.last().value();
+            const CSSValue& value = m_parsedProperties.last().value();
             ImplicitScope implicitScope(this);
             addProperty(properties[1], value, important);
             addProperty(properties[2], value, important);
@@ -2026,17 +2026,16 @@ bool CSSPropertyParser::parse4Values(CSSPropertyID propId, const CSSPropertyID *
         case 2: {
             if (!parseValue(properties[0], important) || !parseValue(properties[1], important))
                 return false;
-            CSSValue value = m_parsedProperties[m_parsedProperties.size() - 2].value();
+            const CSSValue& value = m_parsedProperties[m_parsedProperties.size() - 2].value();
             ImplicitScope implicitScope(this);
             addProperty(properties[2], value, important);
-            value = m_parsedProperties[m_parsedProperties.size() - 2].value();
             addProperty(properties[3], value, important);
             break;
         }
         case 3: {
             if (!parseValue(properties[0], important) || !parseValue(properties[1], important) || !parseValue(properties[2], important))
                 return false;
-            CSSValue value = m_parsedProperties[m_parsedProperties.size() - 2].value();
+            const CSSValue& value = m_parsedProperties[m_parsedProperties.size() - 2].value();
             ImplicitScope implicitScope(this);
             addProperty(properties[3], value, important);
             break;
@@ -2483,7 +2482,7 @@ static bool isFillPositionKeyword(CSSValueID value)
     return value == CSSValueLeft || value == CSSValueTop || value == CSSValueBottom || value == CSSValueRight || value == CSSValueCenter;
 }
 
-void CSSPropertyParser::parse4ValuesFillPosition(CSSParserValueList* valueList, NullableCSSValue& value1, NullableCSSValue& value2, CSSPrimitiveValue parsedValue1, CSSPrimitiveValue parsedValue2)
+void CSSPropertyParser::parse4ValuesFillPosition(CSSParserValueList* valueList, NullableCSSValue& value1, NullableCSSValue& value2, const CSSPrimitiveValue& parsedValue1, const CSSPrimitiveValue& parsedValue2)
 {
     // [ left | right ] [ <percentage] | <length> ] && [ top | bottom ] [ <percentage> | <length> ]
     // In the case of 4 values <position> requires the second value to be a length or a percentage.
@@ -2531,7 +2530,7 @@ void CSSPropertyParser::parse4ValuesFillPosition(CSSParserValueList* valueList,
 
     valueList->next();
 }
-void CSSPropertyParser::parse3ValuesFillPosition(CSSParserValueList* valueList, NullableCSSValue& value1, NullableCSSValue& value2, CSSPrimitiveValue parsedValue1, CSSPrimitiveValue parsedValue2)
+void CSSPropertyParser::parse3ValuesFillPosition(CSSParserValueList* valueList, NullableCSSValue& value1, NullableCSSValue& value2, const CSSPrimitiveValue& parsedValue1, const CSSPrimitiveValue& parsedValue2)
 {
     unsigned cumulativeFlags = 0;
     FillPositionFlag value3Flag = InvalidFillPosition;
@@ -2613,10 +2612,10 @@ void CSSPropertyParser::parse3ValuesFillPosition(CSSParserValueList* valueList,
         value1.swap(value2);
 
 #if ENABLE(ASSERT)
-    CSSPrimitiveValue first = toCSSPrimitiveValue(*value1);
-    CSSPrimitiveValue second = toCSSPrimitiveValue(*value2);
-    ident1 = toCSSPrimitiveValue(*first.getPairValue()->first()).getValueID();
-    ident2 = toCSSPrimitiveValue(*second.getPairValue()->first()).getValueID();
+    const CSSPrimitiveValue& first = toCSSPrimitiveValue(*value1);
+    const CSSPrimitiveValue& second = toCSSPrimitiveValue(*value2);
+    ident1 = first.getPairValue()->first().getValueID();
+    ident2 = second.getPairValue()->first().getValueID();
     ASSERT(ident1 == CSSValueLeft || ident1 == CSSValueRight);
     ASSERT(ident2 == CSSValueBottom || ident2 == CSSValueTop);
 #endif
@@ -2674,6 +2673,7 @@ void CSSPropertyParser::parseFillPosition(CSSParserValueList* valueList, Nullabl
         return;
     }
 
+    // Explicitly make copies.
     CSSPrimitiveValue parsedValue1 = toCSSPrimitiveValue(*value1);
     CSSPrimitiveValue parsedValue2 = toCSSPrimitiveValue(*value2);
 
@@ -5218,7 +5218,7 @@ public:
         allowStyle = property == CSSPropertyBoxShadow;
     }
 
-    void commitLength(CSSPrimitiveValue val)
+    void commitLength(const CSSPrimitiveValue& val)
     {
         if (allowX) {
             x = val;
@@ -5244,7 +5244,7 @@ public:
         }
     }
 
-    void commitColor(CSSPrimitiveValue val)
+    void commitColor(const CSSPrimitiveValue& val)
     {
         color = val;
         allowColor = false;
@@ -5531,7 +5531,7 @@ public:
             m_allowWidth = false;
         }
     }
-    void commitBorderWidth(CSSPrimitiveValue width)
+    void commitBorderWidth(const CSSPrimitiveValue& width)
     {
         m_borderWidth = width;
         m_canAdvance = true;
@@ -5543,7 +5543,7 @@ public:
         m_allowImage = !m_image;
         m_allowRepeat = !m_repeat;
     }
-    void commitBorderOutset(CSSPrimitiveValue outset)
+    void commitBorderOutset(const CSSPrimitiveValue& outset)
     {
         m_outset = outset;
         m_canAdvance = true;
@@ -5653,7 +5653,7 @@ bool CSSPropertyParser::buildBorderImageParseContext(CSSPropertyID propId, Borde
     return context.allowCommit();
 }
 
-void CSSPropertyParser::commitBorderImageProperty(CSSPropertyID propId, NullableCSSValue value, bool important)
+void CSSPropertyParser::commitBorderImageProperty(CSSPropertyID propId, const NullableCSSValue& value, bool important)
 {
     if (value)
         addProperty(propId, *value, important);
@@ -5747,9 +5747,9 @@ public:
     bool allowNumber() const { return m_allowNumber; }
     bool allowFill() const { return m_allowFill; }
     bool allowFinalCommit() const { return m_allowFinalCommit; }
-    NullableCSSValue top() const { return m_top; }
+    const NullableCSSValue& top() const { return m_top; }
 
-    void commitNumber(CSSPrimitiveValue val)
+    void commitNumber(const CSSPrimitiveValue& val)
     {
         if (!m_top)
             m_top = val;
@@ -5853,9 +5853,9 @@ public:
 
     bool allowNumber() const { return m_allowNumber; }
     bool allowFinalCommit() const { return m_allowFinalCommit; }
-    NullableCSSValue top() const { return m_top; }
+    const NullableCSSValue& top() const { return m_top; }
 
-    void commitNumber(CSSPrimitiveValue val)
+    void commitNumber(const CSSPrimitiveValue& val)
     {
         if (!m_top)
             m_top = val;
@@ -5872,9 +5872,9 @@ public:
         m_allowFinalCommit = true;
     }
 
-    void setTop(CSSPrimitiveValue val) { m_top = val; }
+    void setTop(const CSSPrimitiveValue& val) { m_top = val; }
 
-    CSSPrimitiveValue commitBorderImageQuad()
+    const CSSPrimitiveValue commitBorderImageQuad()
     {
         // We need to clone and repeat values for any omissions.
         ASSERT(m_top);