mash: Move shelf model and item classes to ash/common/shelf

mash: Move shelf model and item classes to ash/common/shelf

ShelfModel, ShelfItemDelegate and ShelfItemDelegate have no dependencies on
ash::Shell, ash::RootWindowController or aura::Window so they can be moved
as-is.

No functional changes.

BUG=615155
TEST=compiles

Committed: https://crrev.com/ec04cc3ca7ac5354dd69fa39f149e92e6c19434e
Cr-Commit-Position: refs/heads/master@{#398178}

[James Cook, 2016-06-06 21:30:07]

jamescook@chromium.org changed reviewers:
+ sky@chromium.org

[James Cook, 2016-06-06 21:30:08]

sky, please take a look. This is entirely mechanical, other than removing some
unnecessary #includes on ash/switches.h and ash/shell.h.

[sky, 2016-06-06 23:17:19]

Rubber stamp LGTM

[James Cook, 2016-06-06 23:21:26]

The CQ bit was checked by jamescook@chromium.org

[commit-bot: I haz the power, 2016-06-06 23:22:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2046513003/1

[commit-bot: I haz the power, 2016-06-07 00:52:59]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-06-07 00:54:15]

Description was changed from

==========
mash: Move shelf model and item classes to ash/common/shelf

ShelfModel, ShelfItemDelegate and ShelfItemDelegate have no dependencies on
ash::Shell, ash::RootWindowController or aura::Window so they can be moved
as-is.

No functional changes.

BUG=615155
TEST=compiles
==========

to

==========
mash: Move shelf model and item classes to ash/common/shelf

ShelfModel, ShelfItemDelegate and ShelfItemDelegate have no dependencies on
ash::Shell, ash::RootWindowController or aura::Window so they can be moved
as-is.

No functional changes.

BUG=615155
TEST=compiles

Committed: https://crrev.com/ec04cc3ca7ac5354dd69fa39f149e92e6c19434e
Cr-Commit-Position: refs/heads/master@{#398178}
==========

[commit-bot: I haz the power, 2016-06-07 00:54:16]

Patchset 1 (id:??) landed as
https://crrev.com/ec04cc3ca7ac5354dd69fa39f149e92e6c19434e
Cr-Commit-Position: refs/heads/master@{#398178}