Print Preview: Simplify initializations now that Polymer 1 is removed

Bug: 957738
Change-Id: I0140c1a06b434466c16f46c8ced60285c8654d10
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1592795
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#656118}
2 files changed