GitLab

Adds a UMA use counter to IDBFactory.databases().

Bug: 909000
Change-Id: I3a45c7cccec208fa8d9227bcfb2cc24a4a688324
Reviewed-on: https://chromium-review.googlesource.com/c/1352484Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Daniel Murphy <dmurph@chromium.org>
Reviewed-by: Victor Costan <pwnall@chromium.org>
Commit-Queue: Andreas Butler <andreasbutler@google.com>
Cr-Commit-Position: refs/heads/master@{#612442}