Add virtualKeyboardPrivate.onKeyboardClosed API.

ash/common/wm/panels/panel_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_COMMON_WM_PANELS_PANEL_LAYOUT_MANAGER_H_
 #define ASH_COMMON_WM_PANELS_PANEL_LAYOUT_MANAGER_H_
 
 #include <list>
 #include <memory>
 
@@ skipping 153 matching lines @@
 
   // Called whenever the panel stacking order needs to be updated (e.g. focus
   // changes or a panel is moved).
   void UpdateStacking(WmWindow* active_panel);
 
   // Update the callout arrows for all managed panels.
   void UpdateCallouts();
 
   // Overridden from keyboard::KeyboardControllerObserver:
   void OnKeyboardBoundsChanging(const gfx::Rect& keyboard_bounds) override;
+  void OnKeyboardClosed() override {}
 
   // Parent window associated with this layout manager.
   WmWindow* panel_container_;
 
   WmRootWindowController* root_window_controller_;
 
   // Protect against recursive calls to OnWindowAddedToLayout().
   bool in_add_window_;
   // Protect against recursive calls to Relayout().
   bool in_layout_;
@@ skipping 15 matching lines @@
   // are currently focused.
   WmWindow* last_active_panel_;
   base::WeakPtrFactory<PanelLayoutManager> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PanelLayoutManager);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_WM_PANELS_PANEL_LAYOUT_MANAGER_H_