NavigatorUserMediaError - numeric?

Hello,

some time back, an effort was done to get rid of most cases of numeric 
codes from the specs, and replace them with enumerations of strings.

We have one left:

[NoInterfaceObject]
interface NavigatorUserMediaError {
     const unsigned short PERMISSION_DENIED = 1;
     readonly attribute unsigned short code;
};

Is there any reason this shouldn't be an enum with the single value 
"permission denied"?

                      Harald