Implement position:sticky for table parts

Bug: 702927
Change-Id: I9972f82a8d2b560042b0acbd8484eed5f76f6f2e
Reviewed-on: https://chromium-review.googlesource.com/772412
Commit-Queue: Robert Hogan <robhogan@gmail.com>
Reviewed-by: Morten Stenshorne <mstensho@chromium.org>
Cr-Commit-Position: refs/heads/master@{#517390}
2 files changed