[Touchless][ExploreSites]: Hookup removal code into Most Likely carousel.

This is still hooked up to the ContextMenuManager. Will need Pavel's code
for buttons to fully work.

Bug: 943822
Change-Id: I970a1a8d65bdf513609341bccf329b46fe68a246
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1574250
Commit-Queue: Cathy Li <chili@chromium.org>
Reviewed-by: Justin DeWitt <dewittj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#653278}