Do not parse caption-side: left / right as valid CSS.

third_party/WebKit/Source/core/css/parser/CSSParserFastPaths.cpp

Index: third_party/WebKit/Source/core/css/parser/CSSParserFastPaths.cpp
diff --git a/third_party/WebKit/Source/core/css/parser/CSSParserFastPaths.cpp b/third_party/WebKit/Source/core/css/parser/CSSParserFastPaths.cpp
index 677a4975c4bb6456e2b63f9361d6398009c7a5b3..aa30b74edac99a047ff1c1d1eb0896ab0d20f2e5 100644
--- a/third_party/WebKit/Source/core/css/parser/CSSParserFastPaths.cpp
+++ b/third_party/WebKit/Source/core/css/parser/CSSParserFastPaths.cpp
@@ -536,8 +536,7 @@ bool CSSParserFastPaths::IsValidKeywordPropertyAndValue(
       return value_id == CSSValueAuto || value_id == CSSValueDynamic ||
              value_id == CSSValueStatic;
     case CSSPropertyCaptionSide:
-      return value_id == CSSValueLeft || value_id == CSSValueRight ||
-             value_id == CSSValueTop || value_id == CSSValueBottom;
+      return value_id == CSSValueTop || value_id == CSSValueBottom;
     case CSSPropertyClear:
       return value_id == CSSValueNone || value_id == CSSValueLeft ||
              value_id == CSSValueRight || value_id == CSSValueBoth;