Screen emulation: adjust validation message position.

This is very similar to adjusting context menu and select popup positions.

BUG=355587

Review URL: https://codereview.chromium.org/365883002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@281056 0039d316-1c4b-4281-b951-d872f2087c98
3 files changed