Revert "Cleanup Lookalike interstitial browser tests."

This reverts commit bfa0a0c5.

Reason for revert: Out of an abundance of caution as suspected actual culprit behind https://chromium-review.googlesource.com/c/chromium/src/+/1509333

Original change's description:
> Cleanup Lookalike interstitial browser tests.
> 
> This is a cleanup CL to add a few missing, and simplify existing,
> interstitial tests. It also includes a few unaddressed nits from earlier
> CLs.
> 
> Bug: 927924
> Change-Id: Iaa177d8dfc69d127b6ba2af5c8f508d5e5d8db83
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1497756
> Commit-Queue: Joe DeBlasio <jdeblasio@chromium.org>
> Auto-Submit: Joe DeBlasio <jdeblasio@chromium.org>
> Reviewed-by: Michael Wasserman <msw@chromium.org>
> Reviewed-by: Mustafa Emre Acer <meacer@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#638286}

TBR=msw@chromium.org,meacer@chromium.org,jdeblasio@chromium.org

Change-Id: Ie0b186fd3b3455c13eb1077cb134411416136da2
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 927924
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1509463Reviewed-by: Mustafa Emre Acer <meacer@chromium.org>
Commit-Queue: Joe DeBlasio <jdeblasio@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638738}

chrome/browser/ui/omnibox/alternate_nav_infobar_delegate.cc

@@ -76,7 +76,6 @@ GURL AlternateNavInfoBarDelegate::GetLinkURL() const {
 
 bool AlternateNavInfoBarDelegate::LinkClicked(
     WindowOpenDisposition disposition) {
-  DCHECK(match_);
   history::HistoryService* const history_service =
       HistoryServiceFactory::GetForProfile(profile_,
                                            ServiceAccessType::IMPLICIT_ACCESS);