Kill ui.js

Move remaining ui.js functionality into existing classes and elements.

BUG=400393
NOTRY=true

Review URL: https://codereview.chromium.org/459983002

git-svn-id: svn://svn.chromium.org/blink/trunk@179993 bbb929c8-8fbe-4397-9dbb-9b2b20218538