Fully support the autohide shelf option for touch UI on Windows.

ash/shelf/shelf_layout_manager.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ASH_SHELF_SHELF_LAYOUT_MANAGER_H_
 #define ASH_SHELF_SHELF_LAYOUT_MANAGER_H_
 
 #include <vector>
 
 #include "ash/ash_export.h"
@@ skipping 136 matching lines @@
   ShelfWidget* shelf_widget() { return shelf_; }
 
   // Sets whether any windows overlap the shelf. If a window overlaps the shelf
   // the shelf renders slightly differently.
   void SetWindowOverlapsShelf(bool value);
   bool window_overlaps_shelf() const { return window_overlaps_shelf_; }
 
   void AddObserver(ShelfLayoutManagerObserver* observer);
   void RemoveObserver(ShelfLayoutManagerObserver* observer);
 
-  // Gesture dragging related functions:
+  // Gesture related functions:
+#if defined(OS_WIN)
+  void OnGestureEdgeSwipe(const ui::GestureEvent& gesture);
+#endif
+
   void StartGestureDrag(const ui::GestureEvent& gesture);
   enum DragState {
     DRAG_SHELF,
     DRAG_TRAY
   };
   // Returns DRAG_SHELF if the gesture should continue to drag the entire shelf.
   // Returns DRAG_TRAY if the gesture can start dragging the tray-bubble from
   // this point on.
   DragState UpdateGestureDrag(const ui::GestureEvent& gesture);
   void CompleteGestureDrag(const ui::GestureEvent& gesture);
@@ skipping 243 matching lines @@
   // The show hide animation duration override or 0 for default.
   int duration_override_in_ms_;
 
   DISALLOW_COPY_AND_ASSIGN(ShelfLayoutManager);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_SHELF_SHELF_LAYOUT_MANAGER_H_