mash: Crash right clicking on app list item.
On ToT @ #446703 having built 'chrome' and 'mash:all':
(1) Run chrome --mash
(2) Click on the app list shelf item (circle icon)
(3) Right click on any of the app list items (eg. 'Files').
Expected: The item shows a context menu.
Actual: Crash! (I haven't captured the chrome stack yet)