GitLab

(I'm not sure about other platforms; on Linux, GTK has the weird quirk of
firing "context menu closed" before "context menu item selected", so it's
best to use a solution that doesn't try and track the visibility state of the
context menu).

BUG=none
TEST=manual

Review URL: http://codereview.chromium.org/6335008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@71777 0039d316-1c4b-4281-b951-d872f2087c98