This reverts commit d5274dbb.

Reason for revert:

Findit (https://goo.gl/kROfz5) identified CL at revision 735947 as the
culprit for flakes in the build cycles as shown on:
https://analysis.chromium.org/p/chromium/flake-portal/analysis/culprit?key=ag9zfmZpbmRpdC1mb3ItbWVyQwsSDEZsYWtlQ3VscHJpdCIxY2hyb21pdW0vZDUyNzRkYmI0OGZlMDU2ZGRmNmFlMWNmZjQ2YjQ3OTVkNTU1NDFmOQw

Sample Failed Build: https://ci.chromium.org/b/8889996165162517568

Sample Failed Step: browser_tests

Sample Flaky Test: SecurityTokenSamlTest.Basic

Original change's description:
> Reland Add browser tests for smart card SAML login
> 
> This relands the commit 8fd76b23 that
> got reverted in commit 319c9b41 due to
> failing on official trybots.
> 
> The fix in the reland is to suppress the sync consent screen that is
> normally enabled on the "branded" builds and that was breaking test
> expectations (the test expected the user session to start straight away
> after the successful authentication without any extra screens).
> 
> Original change's description:
> > Add browser tests for smart card SAML login
> >
> > Provide test coverage for the scenario where a new user authenticates
> > via SAML using a smart card (or, generally speaking, using a security
> > token via an extension using the chrome.certificateProvider API).
> >
> > This also provides some test coverage for the <security-token-pin>
> > Polymer element used on the Login Screen.
> >
> > Bug: 1033936
> > Change-Id: I5ded32e0570eb7227c77b954c33d12c1a8a62914
> > Reviewed-on:
> https://chromium-review.googlesource.com/c/chromium/src/+/1968989
> > Reviewed-by: Alexander Alekseev <alemate@chromium.org>
> > Reviewed-by: Denis Kuznetsov [CET] <antrim@chromium.org>
> > Reviewed-by: Alexander Hendrich <hendrich@chromium.org>
> > Commit-Queue: Maksim Ivanov <emaxx@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#734510}
> 
> Bug: 1033936
> Tbr: alemate@chromium.org, hendrich@chromium.org
> Test: run the test locally with is_chrome_branded=true
> Change-Id: I0e8394bb78030137c7570d58c2462a773c13ce06
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2017430
> Commit-Queue: Maksim Ivanov <emaxx@chromium.org>
> Reviewed-by: Denis Kuznetsov [CET] <antrim@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#735947}


Change-Id: Ifc621efff2f069cd90b25f9fff6d778a6732c2c3
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1033936
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2025885
Cr-Commit-Position: refs/heads/master@{#736083}