Add 'X' button to 'Manage search engines' tab order.

Add 'X' button to 'Manage search engines' tab order.

'X' delete button is now part of the focus order in the 'Manage search
engines' options page.

BUG=276874
Committed: https://crrev.com/e0738528aa9effbaaf3d6d8850940f7ff126c24c
Cr-Commit-Position: refs/heads/master@{#300528}

[bondd, 2014-10-20 19:09:57]

bondd@chromium.org changed reviewers:
+ dbeam@chromium.org

[bondd, 2014-10-20 19:09:58]

bondd@chromium.org changed required reviewers:
+ dbeam@chromium.org

[bondd, 2014-10-20 19:21:56]

Breaking issue 664583006 into more CLs, per dbeam@ request in review of that
issue.

[Dan Beam, 2014-10-20 20:20:59]

lgtm

[groby-ooo-7-16, 2014-10-21 17:46:32]

The CQ bit was checked by groby@chromium.org

[commit-bot: I haz the power, 2014-10-21 17:48:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/666823003/1

[commit-bot: I haz the power, 2014-10-21 18:40:35]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-21 18:41:30]

Patchset 1 (id:??) landed as
https://crrev.com/e0738528aa9effbaaf3d6d8850940f7ff126c24c
Cr-Commit-Position: refs/heads/master@{#300528}