Dragging text from 'chrome://settings/searchEngines' leaves input empty.

Delay 'focus' event handler to ensure that 'input' event
is processed first.

BUG=263743
R=arv@chromium.org, tkent@chromium.org

Review URL: https://codereview.chromium.org/39843002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233268 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 233268