Refactors DockedWindowLayoutManager in terms of ash/wm/common

ash/system/tray/tray_image_item.h

Index: ash/system/tray/tray_image_item.h
diff --git a/ash/system/tray/tray_image_item.h b/ash/system/tray/tray_image_item.h
index f9c2659f47e3e4bc9db306d7340965a9dd8d6653..3580c9a986e8f11739b605a031143e706f06a0fc 100644
--- a/ash/system/tray/tray_image_item.h
+++ b/ash/system/tray/tray_image_item.h
@@ -36,11 +36,11 @@ class TrayImageItem : public SystemTrayItem {
   void DestroyDefaultView() override;
   void DestroyDetailedView() override;
   void UpdateAfterLoginStatusChange(user::LoginStatus status) override;
-  void UpdateAfterShelfAlignmentChange(ShelfAlignment alignment) override;
+  void UpdateAfterShelfAlignmentChange(wm::ShelfAlignment alignment) override;
 
  private:
   // Set the alignment of the image depending on the shelf alignment.
-  void SetItemAlignment(ShelfAlignment alignment);
+  void SetItemAlignment(wm::ShelfAlignment alignment);
 
   int resource_id_;
   TrayItemView* tray_view_;