Decrease extension button size + add spacing

This makes ToolbarActionView the same size as other toolbar buttons
instead of increasing its internal size with 4dp to accomodate for
padding between items.

This reduces the BrowserActionsContainer height by 4dp (matching its
current visual height) so it should no longer be able to push the
toolbar height. It also fixes some polish where the spacing left and
right of the browser actions were inadvertedly 10dp instead of 8dp.

Bug: chromium:831393, chromium:916241, chromium:916462
Change-Id: I63e5413ce187f173a5e35b40a3ec8f02a68fa09c
Reviewed-on: https://chromium-review.googlesource.com/c/1394870
Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
Commit-Queue: Peter Boström <pbos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#619999}
5 files changed