DevTools: [Event Listeners] Add "Refresh" button

R=eustas, pfeldman
BUG=341044
NOTRY=true

Review URL: https://codereview.chromium.org/171063005

git-svn-id: svn://svn.chromium.org/blink/trunk@167410 bbb929c8-8fbe-4397-9dbb-9b2b20218538