CrOS Shelf: Use default hit test logic in unknown session state

This should help with flaky tests reported in the linked bug.

Bug: 934558
Change-Id: I78b09e596d7da42c3c483598f62e969fff017309
Reviewed-on: https://chromium-review.googlesource.com/c/1487145
Commit-Queue: Manu Cornet <manucornet@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#635688}
1 file changed