DevTools: update text editor selection on pretty print

This patch updates text editor selection whenever javascript formatting
gets changed.

BUG=302275

Review URL: https://codereview.chromium.org/25346005

git-svn-id: svn://svn.chromium.org/blink/trunk@158632 bbb929c8-8fbe-4397-9dbb-9b2b20218538