cct: reverts ability to not suggest cct visits in omnibox

This is revert of:
https://chromium-review.googlesource.com/c/chromium/src/+/2483342

This was added for an experiment, and is no longer needed. The
experiments for this ended months ago.

By the time this rolls out, the chances of users having the transition
type in their database is pretty slim. None-the-less it is possible. The
worse that would happen is chrome://history shows some visits that
were previously hidden.

This keeps two minor changes:
https://chromium-review.googlesource.com/c/chromium/src/+/2483342/30/components/omnibox/browser/url_index_private_data.cc#452
https://chromium-review.googlesource.com/c/chromium/src/+/2483342/30/content/browser/renderer_host/navigation_controller_impl.cc#2996

BUG=1145206
TEST=none

Change-Id: I749d0c763bc02912852312fed292f7cd73f9658b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2947784
Commit-Queue: Scott Violet <sky@chromium.org>
Reviewed-by: Justin Donnelly <jdonnelly@chromium.org>
Reviewed-by: Charlie Reis <creis@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#890945}