[Media Controls] Fix control layout in small size while playing

This CL modifies inpu element's GetSizeOrDefault method so that
overflow button is included as a button control to prevent not
having a default size which causes layout issue in small size.

Bug: 926142
Change-Id: I5c72acf55d206c611302786b9085667ce41ed11f
Reviewed-on: https://chromium-review.googlesource.com/c/1448994
Commit-Queue: Jazz Xu <jazzhsu@chromium.org>
Reviewed-by: Tommy Steimel <steimel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#628913}
2 files changed