- Explicitly allows construction of
{Named,Indexed}PropertyHandlerConfiguration with all the members filled.

Bug: v8:7612
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: I426ea33846b5dbf2b3482c722c963a6e4b0abded
Reviewed-on: https://chromium-review.googlesource.com/1163882Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55142}