GitLab

Implement conversion from single PNG to PDF image format when requested
by user on scanning UI. Add unit tests to verify functionality.

Bug: b:161237869
Change-Id: I94f383980ff284996008755509e63ed6023be1a4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2547303
Commit-Queue: Kyra Moed <kmoed@google.com>
Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Reviewed-by: Jesse Schettler <jschettler@chromium.org>
Cr-Commit-Position: refs/heads/master@{#833421}