Reland Print Preview: Destinations Dropdown

Update Print Preview to use a dropdown for the destinations settings
section. The dropdown includes the recent destinations, Save as PDF,
and "Save to Google Drive" if the user is signed in.

The destinations dialog is accessible via a "Select destination"
option.

Fixed in reland: tests pass on debug builds by simplifying destination
settings tests and adding additional test in model_test.js to verify
some of the behavior that was being tested by the more complex tests

Bug: 920056
Change-Id: I8be70a25bf2c68841d0109a8d4f57193c4ceacfa
Reviewed-on: https://chromium-review.googlesource.com/c/1415991
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#623568}
20 files changed