GitLab

This CL sets up the class structure for bookmark bottom sheet. Details
will be added in following CLs.

A instrumentation test is also added, which only contains a simple test
to check the bottom sheet opened with a title text view.

Bug: 1128074,1133496
Change-Id: I02d7a488ffa46e9ee4f6993003dfade8e7fbb3b1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2473078
Commit-Queue: Xing Liu <xingliu@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Reviewed-by: Brandon Wylie <wylieb@chromium.org>
Reviewed-by: Matthew Jones <mdjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824564}