ash: Start/stop observing KeyboardController via ShellObserver

chrome/browser/chromeos/login/lock/webui_screen_locker.h

 // Copyright 2014 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 CHROME_BROWSER_CHROMEOS_LOGIN_LOCK_WEBUI_SCREEN_LOCKER_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_LOCK_WEBUI_SCREEN_LOCKER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 120 matching lines @@
 
   // PowerManagerClient::Observer:
   void SuspendImminent() override;
   void SuspendDone(const base::TimeDelta& sleep_duration) override;
   void LidEventReceived(bool open, const base::TimeTicks& time) override;
 
   // content::WebContentsObserver:
   void RenderProcessGone(base::TerminationStatus status) override;
 
   // ash::ShellObserver:
-  void OnVirtualKeyboardStateChanged(bool activated) override;
+  void OnVirtualKeyboardStateChanged(bool activated,
+                                     ash::WmWindow* root_window) override;
 
   // keyboard::KeyboardControllerObserver:
   void OnKeyboardBoundsChanging(const gfx::Rect& new_bounds) override;
   void OnKeyboardClosed() override;
 
   // display::DisplayObserver:
   void OnDisplayAdded(const display::Display& new_display) override;
   void OnDisplayRemoved(const display::Display& old_display) override;
   void OnDisplayMetricsChanged(const display::Display& display,
                                uint32_t changed_metrics) override;
@@ skipping 43 matching lines @@
   bool is_observing_keyboard_ = false;
 
   base::WeakPtrFactory<WebUIScreenLocker> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WebUIScreenLocker);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_LOCK_WEBUI_SCREEN_LOCKER_H_