Add use counter for prefixed intrinsic size keywords

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 bf6ae705ab3d0d4eafd47a67cdc7bfefe7e9422b..a2aa240364015e2f9912db725cd81844922506c8 100644
--- a/Source/core/css/parser/CSSPropertyParser.cpp
+++ b/Source/core/css/parser/CSSPropertyParser.cpp
@@ -375,6 +375,14 @@ bool CSSPropertyParser::validWidthOrHeight(CSSParserValue* value, Units unitless
                 m_context.useCounter()->count(UseCounter::LegacyCSSValueIntrinsic);
             else if (value->id == CSSValueMinIntrinsic)
                 m_context.useCounter()->count(UseCounter::LegacyCSSValueMinIntrinsic);
+            else if (value->id == CSSValueWebkitMinContent)
+                m_context.useCounter()->count(UseCounter::CSSValuePrefixedMinContent);
+            else if (value->id == CSSValueWebkitMaxContent)
+                m_context.useCounter()->count(UseCounter::CSSValuePrefixedMaxContent);
+            else if (value->id == CSSValueWebkitFillAvailable)
+                m_context.useCounter()->count(UseCounter::CSSValuePrefixedFillAvailable);
+            else if (value->id == CSSValueWebkitFitContent)
+                m_context.useCounter()->count(UseCounter::CSSValuePrefixedFitContent);
         }
         return true;
     }