UkmFeatures: Fix GCC build after #617636

This kind of reapplies the same fix landed in
https://chromium-review.googlesource.com/c/chromium/src/+/1273746 after
commit 6bac25cd ("record use counter ukm/uma usage for features on main
frames only").

Due to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84849, having
base::NoDestructor<T<U>> and passing an initializer list of Us does not
work, so explicitly pass an std::initializer_list there to disambiguate
things.

Bug: 819294
Change-Id: Ibe459c61a4df18726223a9ce4a6564a331c26028
Reviewed-on: https://chromium-review.googlesource.com/c/1384525
Commit-Queue: Raphael Kubo da Costa <raphael.kubo.da.costa@intel.com>
Reviewed-by: Bryan McQuade <bmcquade@chromium.org>
Cr-Commit-Position: refs/heads/master@{#618198}
1 file changed