GitLab

Introduce ChromeSupplier and use it to provide OverviewModeBehavior to
the app menu and SystemUiCoordinator/NavigationBarColorController.

The ChromeSupplier allows classes to register a callback to be notified
when the wrapped dependency is available.

BUG=956260, 960129

Change-Id: If1e363be247a237b45931b1727cb76f2a6ee694b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1610205
Commit-Queue: Theresa <twellington@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#661013}