Remove support of nonstandard 'CSSValueCenter' property value for floated element.

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 5dba684a3526f1ce8a86936978b05fc455ace11b..2f0844aa2664005d6530a913360f375a927a7453 100644
--- a/Source/core/css/parser/CSSParserFastPaths.cpp
+++ b/Source/core/css/parser/CSSParserFastPaths.cpp
@@ -210,8 +210,8 @@ bool CSSParserFastPaths::isValidKeywordPropertyAndValue(CSSPropertyID propertyId
             || (RuntimeEnabledFeatures::cssGridLayoutEnabled() && (valueID == CSSValueGrid || valueID == CSSValueInlineGrid));
     case CSSPropertyEmptyCells: // show | hide
         return valueID == CSSValueShow || valueID == CSSValueHide;
-    case CSSPropertyFloat: // left | right | none | center (for buggy CSS, maps to none)
-        return valueID == CSSValueLeft || valueID == CSSValueRight || valueID == CSSValueNone || valueID == CSSValueCenter;
+    case CSSPropertyFloat: // left | right | none
+        return valueID == CSSValueLeft || valueID == CSSValueRight || valueID == CSSValueNone;
     case CSSPropertyFontStyle: // normal | italic | oblique
         return valueID == CSSValueNormal || valueID == CSSValueItalic || valueID == CSSValueOblique;
     case CSSPropertyFontStretch: // normal | ultra-condensed | extra-condensed | condensed | semi-condensed | semi-expanded | expanded | extra-expanded | ultra-expanded