Polish the Global Command UI a bit.

Mainly this switches the scope toggle from an icon to a combo box, since the meaning of that is clearer.

BUG=302437
R=yoz@chromium.org

Review URL: https://codereview.chromium.org/29873004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230405 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230405
Expose the delay for autoclicks in AccessibilityManager.

BUG=272401
TEST=updated AccessibilityManagerTest

Review URL: https://codereview.chromium.org/31083006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230406 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230406