Observes work area change and auto-hide for notifications.

ash/shelf/shelf_layout_manager.h

Index: ash/shelf/shelf_layout_manager.h
diff --git a/ash/shelf/shelf_layout_manager.h b/ash/shelf/shelf_layout_manager.h
index 939a057e4be177705107d15560d63fb42818313e..fb5f96a4a109e45ff842f7d550bf863954cf9563 100644
--- a/ash/shelf/shelf_layout_manager.h
+++ b/ash/shelf/shelf_layout_manager.h
@@ -74,6 +74,8 @@ class ASH_EXPORT ShelfLayoutManager :
   // settings see ash::switches::UseAlternateShelfLayout).
   static const int kShelfSize;
 
+  static int GetPreferredShelfSize();

[James Cook, 2013/07/17 21:14:14]

nit: Add a comment indicating that this is the shelf size when shown.

Also, should kShelfSize be removed from this header, to force callers to use
GetPreferredShelfSize()?  Or is it needed somewhere, like in tests?

[Jun Mukai, 2013/07/18 17:55:43]

comment added.
Some code uses kShelfSize, but it would be because this code is slightly new? 
It seems better to be done in another CL.

+
   explicit ShelfLayoutManager(ShelfWidget* shelf);
   virtual ~ShelfLayoutManager();