Revert of mash: Fix MusPropertyMirrorAsh for owned properties; add test.

ash/wm/window_properties.h

Index: ash/wm/window_properties.h
diff --git a/ash/wm/window_properties.h b/ash/wm/window_properties.h
index 561f18be2213dd9e49de1c90ce498f6d12e3f8b2..c0c3d035f8882af76d13587c6783ddd484f21d2c 100644
--- a/ash/wm/window_properties.h
+++ b/ash/wm/window_properties.h
@@ -47,6 +47,9 @@
 // bounds outside of its root window is set.
 ASH_EXPORT extern const aura::WindowProperty<bool>* const kLockedToRootKey;
 
+// If true (and the window is a panel), it's attached to its shelf item.
+ASH_EXPORT extern const aura::WindowProperty<bool>* const kPanelAttachedKey;
+
 // A property key which stores the bounds to restore a window to. These take
 // preference over the current bounds/state. This is used by e.g. the always
 // maximized mode window manager.
@@ -61,6 +64,9 @@
 
 // A property key to store the id for a window's shelf item.
 ASH_EXPORT extern const aura::WindowProperty<ShelfID>* const kShelfIDKey;
+
+// A property key to store the type of a window's shelf item.
+ASH_EXPORT extern const aura::WindowProperty<int32_t>* const kShelfItemTypeKey;
 
 // Containers with this property (true) are aligned with physical pixel
 // boundary.