Print Preview Componentization: Add timeout to selects

Add a timeout to the select sections, so that the preview does not
immediately begin generating and freeze the dropdown when the value
is changed.

Bug: 773928
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: If217c25420815f56a7c37adde7e97f86bcc99fa3
Reviewed-on: https://chromium-review.googlesource.com/1056216
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#559210}
15 files changed