GitLab

Remove HoverButton::SetStyle() and SetSubtitleColor(), which were being
called only by a test. Also remove some #includes.

Change-Id: I82796f7263763cbc58204b74e02d4e26796f202f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2024271
Commit-Queue: Takumi Fujimoto <takumif@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#736030}