Disable Rotation Animations on Login Pages

This change is intended to M-43. Currently screen rotation animations expose a bug, causing the login screen to not be useable.

Disable rotation animations while a user is not logged in. This will be later reverted on M-44 where a fix to the underlying issue will be landed.

TEST=manual testing on device
BUG=chrome-os-partner:40118
Committed: https://crrev.com/274e83a41a63c1746203bc1cee8cefd07ae821c9
Cr-Commit-Position: refs/heads/master@{#330100}

[jonross, 2015-05-15 14:08:54]

Patchset #1 (id:1) has been deleted

[jonross, 2015-05-15 14:10:18]

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

[jonross, 2015-05-15 14:10:20]

Hi Oshima,

As a potential alternative to disabling the entire screen rotation animation on
M-43, I've been asked to turn it off on login screens.

Could you review this change where I've implemented that?

Thanks,
Jon

[oshima, 2015-05-15 14:41:57]

lgtm

[jonross, 2015-05-15 14:43:56]

The CQ bit was checked by jonross@chromium.org

[commit-bot: I haz the power, 2015-05-15 14:44:08]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1139793003/20001

[commit-bot: I haz the power, 2015-05-15 16:02:47]

Committed patchset #1 (id:20001)

[commit-bot: I haz the power, 2015-05-15 16:03:45]

Patchset 1 (id:??) landed as
https://crrev.com/274e83a41a63c1746203bc1cee8cefd07ae821c9
Cr-Commit-Position: refs/heads/master@{#330100}