GitLab

Moves MockPasswordManagerClient into its own class/file so it can be
used to test the InfobarPasswordCoordinator.

Bug: 945478
Change-Id: I55bb48ffcb0ce88205a0ebef6ba742e7ed667347
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1580349Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Commit-Queue: Sergio Collazos <sczs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#653618}