Assert contents of page in interstitials tests.

This CL allows the interstitials browser tests to verify that displayed
interstitials are the ones expected. Previously, tests only compared the
page titles, which were often shared between different interstitials.

Bug: 891096
Change-Id: Ieb5e9f9a90739cf35f2357655d5e0c31a2a68c91
Reviewed-on: https://chromium-review.googlesource.com/c/1297578
Reviewed-by: Carlos IL <carlosil@chromium.org>
Commit-Queue: Joe DeBlasio <jdeblasio@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602463}
1 file changed