ash::CursorWindowController: handle ui::kCursorNone

ash::CursorWindowController: handle ui::kCursorNone

Setting cursor type to ui::kCursorNone is treated the same as setting
visibility to false.

However note that it is necessary to track the last requested cursor
visibility separately.

BUG=chrome-os-partner:30313
TEST=verify that large cursor disappears in Youtube full-screen mode

Committed: https://crrev.com/3f4880805d3a962590c070f70f6fce904a340aa6
Cr-Commit-Position: refs/heads/master@{#319018}

[hshi1, 2015-03-04 00:25:38]

hshi@chromium.org changed reviewers:
+ oshima@chromium.org

[hshi1, 2015-03-04 00:25:38]

PTAL thanks! This is verified to fix the problem.

[oshima, 2015-03-04 00:56:01]

lgtm

[hshi1, 2015-03-04 00:56:41]

The CQ bit was checked by hshi@chromium.org

[commit-bot: I haz the power, 2015-03-04 00:57:27]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/980453002/20001

[commit-bot: I haz the power, 2015-03-04 04:25:04]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-03-04 04:25:58]

Patchset 2 (id:??) landed as
https://crrev.com/3f4880805d3a962590c070f70f6fce904a340aa6
Cr-Commit-Position: refs/heads/master@{#319018}