(Merge to M-51) Fix Chrome OS shelf locking for chromebook lid open/close.

(Merge to M-51) Fix Chrome OS shelf locking for chromebook lid open/close.

Do not allow shelf alignment changes while locked.
Fixes a regression from https://codereview.chromium.org/1851883002
Extends my earlier fix https://codereview.chromium.org/1877543002

BUG=603243
TEST=Closing/opening chromebook lid with left-aligned shelf works as expected.
R=sky@chromium.org

Review URL: https://codereview.chromium.org/1920073002

Cr-Commit-Position: refs/heads/master@{#389673}
(cherry picked from commit 0d806bc979f45e4dfd4c701c9f518bcff52b23c8)

Committed: https://chromium.googlesource.com/chromium/src/+/f81a9c3501848333033c2a2a196bf475da5a8c38

[msw, 2016-04-27 18:34:12]

Description was changed from

==========
(Merge to M-51) Fix Chrome OS shelf locking for chromebook lid open/close.

Do not allow shelf alignment changes while locked.
Fixes a regression from https://codereview.chromium.org/1851883002
Extends my earlier fix https://codereview.chromium.org/1877543002

BUG=603243
TEST=Closing/opening chromebook lid with left-aligned shelf works as expected.
R=sky@chromium.org

Review URL: https://codereview.chromium.org/1920073002

Cr-Commit-Position: refs/heads/master@{#389673}
(cherry picked from commit 0d806bc979f45e4dfd4c701c9f518bcff52b23c8)
==========

to

==========
(Merge to M-51) Fix Chrome OS shelf locking for chromebook lid open/close.

Do not allow shelf alignment changes while locked.
Fixes a regression from https://codereview.chromium.org/1851883002
Extends my earlier fix https://codereview.chromium.org/1877543002

BUG=603243
TEST=Closing/opening chromebook lid with left-aligned shelf works as expected.
R=sky@chromium.org

Review URL: https://codereview.chromium.org/1920073002

Cr-Commit-Position: refs/heads/master@{#389673}
(cherry picked from commit 0d806bc979f45e4dfd4c701c9f518bcff52b23c8)

Committed:
https://chromium.googlesource.com/chromium/src/+/f81a9c3501848333033c2a2a196b...
==========

[msw, 2016-04-27 18:34:14]

Committed patchset #1 (id:1) manually as
f81a9c3501848333033c2a2a196bf475da5a8c38.