Revert 207755 "Add device policies to control accessibility sett..."

Revert 207755 "Add device policies to control accessibility sett..."

BUG=252670
TBR=bartfab@chromium.org

> Add device policies to control accessibility settings on the login screen
> 
> This CL adds device policies that provide control over the default state
> of the following four accessibility settings on the login screen:
> * Large cursor
> * Spoken feedback
> * High contrast mode
> * Screen magnifier type
> 
> The User can temporarily override the settings but the defaults are
> restored whenever the login screen is shown anew or the user remains idle
> on the login screen for one minute.
> 
> BUG=225955, 225956, 243350, 247298
> TEST=New unittests + new browsertests + manual in VM
> 
> Review URL: https://chromiumcodereview.appspot.com/16658015

TBR=bartfab@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=207799

[Alexander Potapenko, 2013-06-21 11:52:30]

CC eugenis (FYI)

[Alexander Potapenko, 2013-06-21 11:52:42]

Committed patchset #1 manually as r207799.