Polymer.PaperCheckedElementBehavior to implement a custom element
that has a
checked property similar to
and is compatible with having a ripple effect.
Polymer.PaperInkyFocusBehavior implements a ripple when the element has keyboard focus.
Polymer.PaperRippleBehavior dynamically implements a ripple
when the element has focus via pointer or keyboard.
NOTE: This behavior is intended to be used in conjunction with and after