Autocomplete list doesn't hide when clicking away from it in the browser

[bgrins]

From #1091:

STR:

• Type something in a URL bar to get autocomplete list to open
• Click anywhere in the browser (web contents, nav bar...)

Expected:

• Autocompletes go away

The autocomplete list doesn't disappear even when I click elsewhere in the browser. Seems the only way to get it to go away is by pressing ESC - but once I've clicked elsewhere the URL bar loses focus so ESC doesn't close it.