Revert 226895 "Add autoclick accessibility feature to ash."

This seems to be killing ash_unittests in a bad way.
Last three runs on Win Aura Tests (1) in the main waterfall end with:

[----------] 4 tests from AutoclickTest
[ RUN      ] AutoclickTest.ToggleEnabled

command timed out: 600 seconds without output, attempting to kill

> Add autoclick accessibility feature to ash.
> 
> BUG=272401
> TEST=added unit tests
> 
> Review URL: https://codereview.chromium.org/24191002

TBR=tengs@chromium.org

Review URL: https://codereview.chromium.org/25973002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226961 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226961