QA: Avoid issues for Chrome diff browser test

Ensuring that the overlay gets close will help avoid the error
"Other element would receive the click:
<div class="overlay editor-overlay">...</div> "

Found here for example:
http://bit.ly/1gyXrOR

Change-Id: Ib4a0ae434e3a71a6aec4a7996124e8292098da4a
Merge "QA: Avoid issues for Chrome diff browser test"