GitLab

Add resource_coordinator::TabManagerTest::tab_manager_.

Having a single TabManager initialization path in TabManagerTest
will simplify adding common initialization code in an upcoming CL.

Bug: 775644
Change-Id: Icb648e1591127a1a5f4acf847208cd53e2dfb278
Reviewed-on: https://chromium-review.googlesource.com/820201Reviewed-by: Chris Hamilton <chrisha@chromium.org>
Reviewed-by: Sébastien Marchand <sebmarchand@chromium.org>
Commit-Queue: François Doray <fdoray@chromium.org>
Cr-Commit-Position: refs/heads/master@{#524065}