add pan-x and pan-y support to CSS touch-action parsing.

Source/core/css/CSSPrimitiveValueMappings.h

Index: Source/core/css/CSSPrimitiveValueMappings.h
diff --git a/Source/core/css/CSSPrimitiveValueMappings.h b/Source/core/css/CSSPrimitiveValueMappings.h
old mode 100644
new mode 100755
index 4b5b0a4c8493ad9548173f1ff8e6c1a91db761cc..c07b4ab77858db342329d2ea1e6439d27c50914d
--- a/Source/core/css/CSSPrimitiveValueMappings.h
+++ b/Source/core/css/CSSPrimitiveValueMappings.h
@@ -4877,6 +4877,12 @@ template<> inline CSSPrimitiveValue::CSSPrimitiveValue(TouchAction t)
     case TouchActionAuto:
         m_value.valueID = CSSValueAuto;
         break;
+    case TouchActionPanX:
+        m_value.valueID = CSSValuePanX;
+        break;
+    case TouchActionPanY:
+        m_value.valueID = CSSValuePanY;
+        break;
     }
 }
 
@@ -4888,6 +4894,10 @@ template<> inline CSSPrimitiveValue::operator TouchAction() const
         return TouchActionNone;
     case CSSValueAuto:
         return TouchActionAuto;
+    case CSSValuePanX:
+        return TouchActionPanX;
+    case CSSValuePanY:
+        return TouchActionPanY;
     default:
         break;
     }