[ios] Fix "showing undo button on recent tab page on iPad"

Previously, on iPad, when use click on "Close All" on regular tab page,
the recent tab page will also show an "Undo" button as regular tab page
does. That's because the "Close All" button haven't been configured for
recent tab page on iPad. The configuration logic was incorrectly removed
in https://crrev.com/c/2683714, because only iPhone bottom toolbar has
been checked and there is a different between iPhone bottom toolbar and
iPad top toolbar -- iPhone bottom toolbar of the recent tabs page
doesn't have an enabled "Close All" button.

To fix this, add the configuration sentences back to configure the
"Close All" button on top toolbar of iPad.

Bug: 1191997
Change-Id: I9e58a9e8d4232db1b2a478d500e7d124891f508f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2792723
Commit-Queue: Tina Wang <tinazwang@chromium.org>
Reviewed-by: edchin <edchin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#867353}