GitLab

This CL implements support for multiselect in holding space. Previously
it was only possible to operate on a single holding space item at a time
but following this change it is possible to perform bulk operations.

Bug: 1129981
Change-Id: I9bf82e748fa6f145af061b2ba8ffae2948cf48c9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2429433Reviewed-by: Ahmed Mehfooz <amehfooz@chromium.org>
Commit-Queue: David Black <dmblack@google.com>
Cr-Commit-Position: refs/heads/master@{#810898}