IDL parser: Drop accepting extended attributes on enum values

For now, IDL parser allows to put extended attributes on enum values,
that is syntactically invalid in Web IDL spec [1].
In Blink, other IDL compiler parts ignore them, and no IDL files have them.

In order to avoid misleading developers, this CL makes IDL parser
to disallow extended attributes on enum values.

[1] https://heycam.github.io/webidl/#idl-enums


Bug: 871867
Change-Id: Ic57406ce3ff94a0c1a4cf38da12b217c05667eb0
Reviewed-on: https://chromium-review.googlesource.com/1169482
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Yuki Shiino <yukishiino@chromium.org>
Commit-Queue: Hitoshi Yoshida <peria@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#582009}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 36fcc8ace288e10163895764608c716b8eccd9f5
1 file changed