Revert "Extensions: Focus correct button on options dialog close."

This reverts commit 520af7b3824dd819dd134c926024234efd38e301.

Reason for revert:

Findit (https://goo.gl/kROfz5) identified CL at revision 622110 as the
culprit for flakes in the build cycles as shown on:
https://findit-for-me.appspot.com/waterfall/flake/flake-culprit?key=ag9zfmZpbmRpdC1mb3ItbWVyQwsSDEZsYWtlQ3VscHJpdCIxY2hyb21pdW0vNTIwYWY3YjM4MjRkZDgxOWRkMTM0YzkyNjAyNDIzNGVmZDM4ZTMwMQw

Sample Failed Build: https://ci.chromium.org/buildbot/chromium.mac/Mac10.12%20Tests/18532

Sample Failed Step: network_service_browser_tests on Intel GPU on Mac on Mac-10.12.6

Sample Flaky Test: CrExtensionsManagerTestWithOptionsDialog.ShowOptionsDialog

Original change's description:
> Extensions: Focus correct button on options dialog close.
> 
> Also fix some const references surfaced by presubmit.
> 
> Bug: 912026
> Change-Id: If18dc61d8284c86cbec9f23e09286e9c5f666824
> Reviewed-on: https://chromium-review.googlesource.com/c/1405459
> Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
> Commit-Queue: Hector Carmona <hcarmona@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#622110}

Change-Id: I28c92c8792556c3db05081a4aa2df3fe0eb91e91
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 912026, 921212
Reviewed-on: https://chromium-review.googlesource.com/c/1407786
Cr-Commit-Position: refs/heads/master@{#622210}
5 files changed