GitLab

Move aura window properties to WmWindowAura.
(towards supporting [Shelf]WindowWatcher in mash)

Cleanup ShelfItem and ShelfItemDetails structs.
Remove unused ash support for UserManagerView

BUG=634150
TEST=Automated tests; no shelf functionality changes.
R=sky@chromium.org

Review-Url: https://codereview.chromium.org/2332393003
Cr-Commit-Position: refs/heads/master@{#418723}