This makes Chrome export a SetDisplayPower D-Bus method call
for the power manager.
It also reworks OutputConfigurator to cache the
most-recently-requested power state and use it for future
display mode requests.
Finally, it works around a related bug where multiple mouse
events may be generated when the displays are reconfigured,
which would result in a report of user activity that could
abort suspending.
BUG=chromium-os:39289,180348,chrome-os-partner:12662
TBR=sky@chromium.org
Review URL: https://chromiumcodereview.appspot.com/12391004
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@186625 0039d316-1c4b-4281-b951-d872f2087c98
8405db5338