Rename InputType class in InputTypeUI.{cpp,h} to InputTypeUI.

This is a preparation to separate InputType class into two.

BUG=274205
TEST=none; These files are not compiled yet.
R=keishi@chromium.org

Review URL: https://codereview.chromium.org/22821007

git-svn-id: svn://svn.chromium.org/blink/trunk@156544 bbb929c8-8fbe-4397-9dbb-9b2b20218538