Connect tooltip keydown listener.
Connect tooltip keydown listener.

jupyter/jupyter-js-notebook,blink1073/jupyter-js-notebook,jupyter/jupyter-js-notebook,jupyter/jupyter-js-notebook,blink1073/jupyter-js-notebook,blink1073/jupyter-js-notebook,jupyter/jupyter-js-notebook,blink1073/jupyter-js-notebook,jupyter/jupyter-js-notebook,blink1073/jupyter-js-notebook