Revert 234300 "Make LabelButton respect the minimum size of its ..."

> Make LabelButton respect the minimum size of its border.  This is useful for
> e.g. LabelButtonBorders containing painters with minimum sizes, so the embedder
> doesn't have to calculate and enforce the minimum size manually.
> 
> BUG=none
> TEST=none
> R=msw@chromium.org, sky@chromium.org
> 
> Review URL: https://codereview.chromium.org/64743004

TBR=pkasting@chromium.org

Review URL: https://codereview.chromium.org/66033008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@234311 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 234311