mash: Convert AshPopupAlignmentDelegate to wm common types

ash/shelf/shelf.h

Index: ash/shelf/shelf.h
diff --git a/ash/shelf/shelf.h b/ash/shelf/shelf.h
index 66c23b266464fd67eda3d362e7b2b7c55a6daf54..005df1c62d2c800cdfb48368fb6d55727d0145d6 100644
--- a/ash/shelf/shelf.h
+++ b/ash/shelf/shelf.h
@@ -68,10 +68,6 @@ class ASH_EXPORT Shelf {
   // user is logged in yet.
   static Shelf* ForWindow(const aura::Window* window);
 
-  // Returns the shelf for the display with |display_id| or null if that display
-  // does not exist or does not have a shelf.
-  static Shelf* ForDisplayId(int64_t display_id);
-
   void SetAlignment(ShelfAlignment alignment);
   ShelfAlignment alignment() const { return alignment_; }
   bool IsHorizontalAlignment() const;