mash: Move AutoHideEventHandler to WmShelfAura.

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 ff6439a563e2c45e341001873e292ed1d1fb8ee3..1299bf5e03319d79780101c92ba80bba16d3b42d 100644
--- a/ash/aura/wm_shelf_aura.h
+++ b/ash/aura/wm_shelf_aura.h
@@ -35,6 +35,8 @@ class ASH_EXPORT WmShelfAura : public WmShelf,
   static Shelf* GetShelf(WmShelf* shelf);
 
  private:
+  class AutoHideEventHandler;
+
   void ResetShelfLayoutManager();
 
   // WmShelf:
@@ -57,8 +59,6 @@ class ASH_EXPORT WmShelfAura : public WmShelf,
   void UpdateIconPositionForWindow(WmWindow* window) override;
   gfx::Rect GetScreenBoundsOfItemIconForWindow(WmWindow* window) override;
   bool ProcessGestureEvent(const ui::GestureEvent& event) override;
-  void UpdateAutoHideForMouseEvent(ui::MouseEvent* event) override;
-  void UpdateAutoHideForGestureEvent(ui::GestureEvent* event) override;
   void AddObserver(WmShelfObserver* observer) override;
   void RemoveObserver(WmShelfObserver* observer) override;
   void SetKeyboardBoundsForTesting(const gfx::Rect& bounds) override;
@@ -83,6 +83,9 @@ class ASH_EXPORT WmShelfAura : public WmShelf,
 
   base::ObserverList<WmShelfObserver> observers_;
 
+  // Forwards mouse and gesture events to ShelfLayoutManager for auto-hide.
+  std::unique_ptr<AutoHideEventHandler> auto_hide_event_handler_;
+
   DISALLOW_COPY_AND_ASSIGN(WmShelfAura);
 };