Revert of Moving coordinate conversion methods from ash/wm to ui/wm. (https://coderev...

Revert of Moving coordinate conversion methods from ash/wm to ui/wm. (https://codereview.chromium.org/425363002/)

Reason for revert:
Build break.

../../ash/display/mouse_cursor_event_filter_ozone.cc:21:7:error: no member named 'ConvertPointToScreen' in namespace 'ash::wm'
  wm::ConvertPointToScreen(target, &point_in_screen);
  ~~~~^
../../ash/display/mouse_cursor_event_filter_ozone.cc:45:7:error: no member named 'ConvertPointFromScreen' in namespace 'ash::wm'
  wm::ConvertPointFromScreen(root_at_point, &point_in_root);
  ~~~~^
../../ash/display/mouse_cursor_event_filter_ozone.cc:86:7:error: no member named 'ConvertPointFromScreen' in namespace 'ash::wm'
  wm::ConvertPointFromScreen(dst_root, &point_in_dst_screen);
  ~~~~^

Original issue's description:
> Moving coordinate conversion methods from ash/wm to ui/wm.
>
> Moving ConvertPointToScreen and ConvertPointFromScreen from ash::wm into
> aura::Window. The suggestion to do this was made here:
> https://codereview.chromium.org/420603011/diff/1/athena/wm/coordinate_conversion.h
>
> BUG=NONE
>
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=287609

TBR=oshima@chromium.org,ben@chromium.org,sky@chromium.org,mfomitchev@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=NONE

Review URL: https://codereview.chromium.org/445703005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@287626 0039d316-1c4b-4281-b951-d872f2087c98