Refactors DockedWindowLayoutManager in terms of ash/wm/common

ash/shelf/shelf_widget.h

Index: ash/shelf/shelf_widget.h
diff --git a/ash/shelf/shelf_widget.h b/ash/shelf/shelf_widget.h
index 3a0d8ff4513f1373ae2a0b405c860b535ee81756..0db944f962e2c4fac4cb71dff5bf936d7be2e2fe 100644
--- a/ash/shelf/shelf_widget.h
+++ b/ash/shelf/shelf_widget.h
@@ -39,12 +39,12 @@ class ASH_EXPORT ShelfWidget : public views::Widget,
   static bool ShelfAlignmentAllowed();
 
   void OnShelfAlignmentChanged();
-  ShelfAlignment GetAlignment() const;
+  wm::ShelfAlignment GetAlignment() const;
 
   // Sets the shelf's background type.
-  void SetPaintsBackground(ShelfBackgroundType background_type,
+  void SetPaintsBackground(wm::ShelfBackgroundType background_type,
                            BackgroundAnimatorChangeType change_type);
-  ShelfBackgroundType GetBackgroundType() const;
+  wm::ShelfBackgroundType GetBackgroundType() const;
 
   // Hide the shelf behind a black bar during e.g. a user transition when |hide|
   // is true. The |animation_time_ms| will be used as animation duration.