[Duet] Three button tab switcher bottom toolbar

This CL makes the tab switcher bottom bar have three buttons:
close all tabs, new tab, and menu buttons.

(cherry picked from commit 83dc750f4d6228c2f0efb916d88b452d2f9b31c1)

Bug: 914039
Change-Id: Ibf3555e838d6c63327c197dd16b0a5529b02db3f
Reviewed-on: https://chromium-review.googlesource.com/c/1364069
Commit-Queue: Pedro Amaral <amaralp@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Reviewed-by: Matthew Jones <mdjones@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#616184}
Reviewed-on: https://chromium-review.googlesource.com/c/1378972
Reviewed-by: Pedro Amaral <amaralp@chromium.org>
Cr-Commit-Position: refs/branch-heads/3626@{#382}
Cr-Branched-From: d897fb137fbaaa9355c0c93124cc048824eb1e65-refs/heads/master@{#612437}
17 files changed