Remove unused KeyboardUI::Show

ash/common/keyboard/keyboard_ui.h

 // Copyright 2016 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_KEYBOARD_KEYBOARD_UI_H_
 #define ASH_COMMON_KEYBOARD_KEYBOARD_UI_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
 
 namespace ash {
 
 class KeyboardUIObserver;
 
 // KeyboardUI wraps the appropriate keyboard ui depending upon whether ash is
 // running in mus or non-mus.
 class ASH_EXPORT KeyboardUI {
  public:
   virtual ~KeyboardUI();
 
   static std::unique_ptr<KeyboardUI> Create();
 
-  virtual void Show() = 0;
   virtual void ShowInDisplay(const int64_t display_id) = 0;
   virtual void Hide() = 0;
 
   // Returns true if the keyboard is enabled.
   virtual bool IsEnabled() = 0;
 
   void AddObserver(KeyboardUIObserver* observer);
   void RemoveObserver(KeyboardUIObserver* observer);
 
   // Applist also queries this for bounds. If app list remains in ash then
   // we need to plumb bounds through here too.
 
  protected:
   KeyboardUI();
 
   base::ObserverList<KeyboardUIObserver>* observers() { return &observers_; }
 
  private:
   base::ObserverList<KeyboardUIObserver> observers_;
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_KEYBOARD_KEYBOARD_UI_H_