Implement direction-specific touch-action values (blink side)

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 2a75bc4104411f8f2a1f5c336bd56bf570699492..d7af1ae8fb1a4a2b82fa484d8bf875a34d2a609a 100644
--- a/Source/core/css/parser/CSSPropertyParser.cpp
+++ b/Source/core/css/parser/CSSPropertyParser.cpp
@@ -7307,13 +7307,32 @@ PassRefPtrWillBeRawPtr<CSSValue> CSSPropertyParser::parseTouchAction()
         return list.release();
     }
 
+    bool xSet = false;
+    bool ySet = false;
     while (value) {
         switch (value->id) {
         case CSSValuePanX:
-        case CSSValuePanY: {
+        case CSSValuePanRight:
+        case CSSValuePanLeft: {
+            if (xSet)
+                return nullptr;
+            xSet = true;
+            if (value->id != CSSValuePanX && !RuntimeEnabledFeatures::cssTouchActionPanDirectionsEnabled())
+                return nullptr;
+
             RefPtrWillBeRawPtr<CSSValue> panValue = cssValuePool().createIdentifierValue(value->id);
-            if (list->hasValue(panValue.get()))
+            list->append(panValue.release());
+            break;
+        }
+        case CSSValuePanY:
+        case CSSValuePanDown:
+        case CSSValuePanUp: {
+            if (ySet)
                 return nullptr;
+            ySet = true;
+            if (value->id != CSSValuePanY && !RuntimeEnabledFeatures::cssTouchActionPanDirectionsEnabled())
+                return nullptr;
+            RefPtrWillBeRawPtr<CSSValue> panValue = cssValuePool().createIdentifierValue(value->id);
             list->append(panValue.release());
             break;
         }