Print Preview: Add test for hiding preview behavior

Test that the preview hides when the user clicks print before the
preview has loaded if the printer is local, and that the preview
remains open until the preview loads if printing to PDF.

Bug: 865544
Change-Id: I1fd89a565f65f4aa0c8115facc8817478896b141
Reviewed-on: https://chromium-review.googlesource.com/1153621
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579209}
4 files changed