Handle null isIncognito in HistoryManger#openUrl

https://chromium-review.googlesource.com/c/chromium/src/+/935263
failed to take into account the fact that isIncognito can be null at
times. Whoops.

Bug: 817032
Change-Id: If050d39445de2ecaaf54c407f13d72347ef6283a
Reviewed-on: https://chromium-review.googlesource.com/940101
Reviewed-by: Maria Khomenko <mariakhomenko@chromium.org>
Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
Cr-Commit-Position: refs/heads/master@{#539614}
1 file changed