mash: Convert StatusAreaWidgetDelegate to wm common types

ash/aura/wm_shelf_aura.h

Index: ash/aura/wm_shelf_aura.h
diff --git a/ash/aura/wm_shelf_aura.h b/ash/aura/wm_shelf_aura.h
index 34bf08fd9980693751ee006111cb2f180f74ad43..148828779da5a64640c5860f4301d3609ccfe982 100644
--- a/ash/aura/wm_shelf_aura.h
+++ b/ash/aura/wm_shelf_aura.h
@@ -9,6 +9,7 @@
 #include "ash/common/shelf/wm_shelf.h"
 #include "ash/shelf/shelf_icon_observer.h"
 #include "ash/shelf/shelf_layout_manager_observer.h"
+#include "ash/wm/gestures/shelf_gesture_handler.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
 
@@ -54,6 +55,8 @@ class ASH_EXPORT WmShelfAura : public WmShelf,
   gfx::Rect GetUserWorkAreaBounds() const override;
   void UpdateIconPositionForWindow(WmWindow* window) override;
   gfx::Rect GetScreenBoundsOfItemIconForWindow(WmWindow* window) override;
+  bool ProcessGestureEvent(const ui::GestureEvent& event,
+                           WmWindow* target_window) override;
   void UpdateAutoHideForMouseEvent(ui::MouseEvent* event) override;
   void UpdateAutoHideForGestureEvent(ui::GestureEvent* event) override;
   void AddObserver(WmShelfObserver* observer) override;
@@ -76,6 +79,9 @@ class ASH_EXPORT WmShelfAura : public WmShelf,
   // Cached separately because it may be destroyed before |shelf_|.
   ShelfLayoutManager* shelf_layout_manager_ = nullptr;
 
+  // Handler for swipe and drag gestures.
+  ShelfGestureHandler gesture_handler_;
+
   base::ObserverList<WmShelfObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(WmShelfAura);