Removes FocusableBorder::set_has_focus

FocusableBorder is passed the view and can determine focus from it.

BUG=none
TEST=none
R=ben@chromium.org

Review URL: https://codereview.chromium.org/102463002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238699 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 238699