Do not accept CSS-wide keywords for descriptors

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 c378fc45ba617776492f9f5bd49246676a20e223..e8c8a824d4d7345a5f6a0d9ab9a92534d70c9479 100644
--- a/third_party/WebKit/Source/core/css/parser/CSSParserFastPaths.cpp
+++ b/third_party/WebKit/Source/core/css/parser/CSSParserFastPaths.cpp
@@ -844,6 +844,10 @@ static CSSValue* parseKeywordValue(CSSPropertyID propertyId, const String& strin
         // Parse initial/inherit shorthands using the CSSPropertyParser.
         if (shorthandForProperty(propertyId).length())
             return nullptr;
+
+        // Descriptors do not support css wide keywords.
+        if (CSSPropertyMetadata::isDescriptor(propertyId))

[Timothy Loh, 2016/05/19 05:44:42]

Maybe this check should just be at the top of the function. font-display is
apparently handled by the keyword fast path currently.

[rwlbuis, 2016/05/20 00:51:11]

This was placed here to minimize calls to isDescriptor. I can still move it if
you want.

+            return nullptr;
     }
 
     CSSParserString cssString;