GitLab

All supporting code now assumes STYLE_TEXTBUTTON, so we no longer need
this enum or supporting code.

BUG=642920

Change-Id: I4817a8383f9e6470f2950767ea5a2f5805a5755c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1636481
Commit-Queue: Robert Liao <robliao@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#664849}