Revert 138212 - Implement High Contrast mode for Chrome OS.

Revert 138212 - Implement High Contrast mode for Chrome OS.

-Add controller to ash for managing the state of High Contrast mode
-Add API to shell to allow Chromium to turn the mode on and off
-Add the option to the Chromium OS accessibility settings page.
-Add functions to layer.cc/h to enable an inversion filter.

This change breaks the build on the Windows canaries after WebKit r117864 due
to a change in the the Chromium WebFilterOperation API.

See
http://build.chromium.org/p/chromium.webkit/builders/Win%20Builder/builds/22082
and https://bugs.webkit.org/show_bug.cgi?id=87046.

BUG=chromium-os:30678
Review URL: https://chromiumcodereview.appspot.com/10201014

TBR=zork@chromium.org
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=138239