[iOS] Add test support for ChromeTableViewController

This CL adds a class to ease testing of subclasses of
ChromeTableViewController, in the same way CollectionViewControllerTest
is easing the testing of subclasses of CollectionViewController.

Bug: 894791
Cq-Include-Trybots: luci.chromium.try:ios-simulator-cronet;luci.chromium.try:ios-simulator-full-configs
Change-Id: I159849612b16d5475d581c79601f93de04e6b705
Reviewed-on: https://chromium-review.googlesource.com/c/1283025
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600706}
3 files changed