[svg2] Make SVGLength wrap a CSSPrimitiveValue

Source/core/css/parser/CSSParserFastPaths.cpp

Index: Source/core/css/parser/CSSParserFastPaths.cpp
diff --git a/Source/core/css/parser/CSSParserFastPaths.cpp b/Source/core/css/parser/CSSParserFastPaths.cpp
index 396eefebe85ee14abd4230e61d1c7672839855af..ad5253d317eb783814850943c71fe30f7c7ba8e4 100644
--- a/Source/core/css/parser/CSSParserFastPaths.cpp
+++ b/Source/core/css/parser/CSSParserFastPaths.cpp
@@ -106,10 +106,12 @@ static PassRefPtrWillBeRawPtr<CSSValue> parseSimpleLengthValue(CSSPropertyID pro
     }
 
     if (unit == CSSPrimitiveValue::CSS_NUMBER) {
-        bool quirksMode = isQuirksModeBehavior(cssParserMode);
-        if (number && !quirksMode)
-            return nullptr;
-        unit = CSSPrimitiveValue::CSS_PX;
+        if (!isUnitLessLengthParsingEnabledForMode(cssParserMode)) {
+            bool quirksMode = isQuirksModeBehavior(cssParserMode);
+            if (number && !quirksMode)
+                return nullptr;
+            unit = CSSPrimitiveValue::CSS_PX;
+        }
     }
     if (number < 0 && !acceptsNegativeNumbers)
         return nullptr;