cros: Remove some OS platform ifdefs from ash

ash/mus/bridge/wm_shell_mus.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_MUS_BRIDGE_WM_SHELL_MUS_H_
 #define ASH_MUS_BRIDGE_WM_SHELL_MUS_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 92 matching lines @@
   SessionStateDelegate* GetSessionStateDelegate() override;
   void AddActivationObserver(WmActivationObserver* observer) override;
   void RemoveActivationObserver(WmActivationObserver* observer) override;
   void AddDisplayObserver(WmDisplayObserver* observer) override;
   void RemoveDisplayObserver(WmDisplayObserver* observer) override;
   void AddPointerWatcher(views::PointerWatcher* watcher,
                          views::PointerWatcherEventTypes events) override;
   void RemovePointerWatcher(views::PointerWatcher* watcher) override;
   void RequestShutdown() override;
   bool IsTouchDown() override;
-#if defined(OS_CHROMEOS)
   void ToggleIgnoreExternalKeyboard() override;
   void SetLaserPointerEnabled(bool enabled) override;
-#endif
 
  private:
   friend class WmShellMusTestApi;
 
   // aura::client::ActivationChangeObserver:
   void OnWindowActivated(ActivationReason reason,
                          aura::Window* gained_active,
                          aura::Window* lost_active) override;
 
   WindowManager* window_manager_;
@@ skipping 11 matching lines @@
 
   base::ObserverList<WmActivationObserver> activation_observers_;
 
   DISALLOW_COPY_AND_ASSIGN(WmShellMus);
 };
 
 }  // namespace mus
 }  // namespace ash
 
 #endif  // ASH_MUS_BRIDGE_WM_SHELL_MUS_H_