Drop [NotEnumerable] from various toString() operations

Drop [NotEnumerable] from various toString() operations

Web IDL does not support non-enumerable stringifiers:
  http://heycam.github.io/webidl/#es-stringifier
It does support unforgeable stringifiers, but that doesn't affect
enumerability, only configurability and writability.

DOM 4 defines DOMTokenList's stringifier without any extended attributes:
  http://w3c.github.io/dom/#interface-domtokenlist

URL defines URLUtils's (and URLUtilsReadOnly's) stringifier without any
extended attributes:
  http://url.spec.whatwg.org/#urlutils
And since it's defined as "stringifier attribute DOMString href;" adding
[NotEnumerable] is ambigious and, depending on interpretation, incorrect,
since the 'href' attribute should certainly be enumerable.

Firefox Nightly has enumerable 'toString' properties on all of Selection,
DOMTokenList and URLUtils.

Given all of this, there also doesn't appear to be a strong reason to have
WebKitCSSMatrix's 'toString' non-enumerable.

Remaining stringifiers not affected by this patch: DOMException, Window
and Location. DOMException is an exception, and thus can't have a
stringifier according to Web IDL, and Window and Location are pretty much
just special.

BUG=306606

[Jens Widell, 2014-06-23 11:43:35]

arv: please review, and/or suggest other reviewers.

A preparation for supporting the stringifier keyword, although it's really only
in the

  [XXX] stringifier attribute DOMString yyy;

case that there's a real issue. My implementation of stringifier is likely to
support [NotEnumerable] on stringifiers just fine in practice (by not making an
exception for it.)

[arv (Not doing code reviews), 2014-06-23 15:49:10]

On 2014/06/23 at 11:43:35, jl wrote:
> arv: please review, and/or suggest other reviewers.
> 
> A preparation for supporting the stringifier keyword, although it's really
only in the
> 
>   [XXX] stringifier attribute DOMString yyy;
> 
> case that there's a real issue. My implementation of stringifier is likely to
support [NotEnumerable] on stringifiers just fine in practice (by not making an
exception for it.)

I'm worried about this change. toString has historically always been non
enumerable in JavaScript and having DOM contradict that seems unfortunate.

I agree that href below should be enumerable,

stringifier attribute DOMString href;

but toString should not.

let me file a bug on webidl to get this cleared up.

[arv (Not doing code reviews), 2014-06-23 15:51:00]

https://www.w3.org/Bugs/Public/show_bug.cgi?id=26179