chromeos: Fix shelf appearing at login screen under mash

ash/common/wm_shell.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_WM_SHELL_H_
 #define ASH_COMMON_WM_SHELL_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <vector>
 
 #include "ash/ash_export.h"
 #include "ash/common/metrics/gesture_action_type.h"
 #include "ash/common/metrics/user_metrics_action.h"
+#include "ash/common/session/session_state_observer.h"
 #include "ash/common/wm/lock_state_observer.h"
 #include "base/observer_list.h"
 #include "components/ui_devtools/devtools_server.h"
 #include "ui/base/ui_base_types.h"
 #include "ui/compositor/layer_type.h"
 #include "ui/wm/public/window_types.h"
 
 namespace app_list {
 class AppList;
 }
@@ skipping 67 matching lines @@
 class MaximizeModeEventHandler;
 class WindowState;
 }
 
 #if defined(OS_CHROMEOS)
 class LogoutConfirmationController;
 class VpnList;
 #endif
 
 // Similar to ash::Shell. Eventually the two will be merged.
-class ASH_EXPORT WmShell {
+class ASH_EXPORT WmShell : public SessionStateObserver {
  public:
   // This is necessary for a handful of places that is difficult to plumb
   // through context.
   static void Set(WmShell* instance);
   static WmShell* Get();
   static bool HasInstance() { return instance_ != nullptr; }
 
   void Initialize(const scoped_refptr<base::SequencedWorkerPool>& pool);
   virtual void Shutdown();
 
@@ skipping 222 matching lines @@
   CreateScopedDisableInternalMouseAndKeyboard() = 0;
 
   virtual std::unique_ptr<ImmersiveFullscreenController>
   CreateImmersiveFullscreenController() = 0;
 
   virtual std::unique_ptr<KeyEventWatcher> CreateKeyEventWatcher() = 0;
 
   // Initializes the appropriate shelves. Does nothing for any existing shelves.
   void CreateShelf();
 
-  // Show shelf view if it was created hidden (before session has started).
-  void ShowShelf();
-
   void CreateShelfDelegate();
 
   // Called after maximize mode has started, windows might still animate though.
   void OnMaximizeModeStarted();
 
   // Called after maximize mode has ended, windows might still be returning to
   // their original position.
   void OnMaximizeModeEnded();
 
   // Called when the overview mode is about to be started (before the windows
@@ skipping 80 matching lines @@
 
   // TODO(jamescook): Remove this when VirtualKeyboardController has been moved.
   virtual void ToggleIgnoreExternalKeyboard() = 0;
 
   // Enable or disable the laser pointer.
   virtual void SetLaserPointerEnabled(bool enabled) = 0;
 #endif
 
  protected:
   explicit WmShell(std::unique_ptr<ShellDelegate> shell_delegate);
-  virtual ~WmShell();
+  ~WmShell() override;
 
   base::ObserverList<ShellObserver>* shell_observers() {
     return &shell_observers_;
   }
 
   void SetKeyboardUI(std::unique_ptr<KeyboardUI> keyboard_ui);
 
   // Helpers to set (and initialize) or destroy various delegates.
   // TODO(msw|jamescook): Remove these once ShellDelegate, etc. are ported.
   void SetSystemTrayDelegate(std::unique_ptr<SystemTrayDelegate> delegate);
   void DeleteSystemTrayDelegate();
 
   void DeleteWindowCycleController();
 
   void DeleteWindowSelectorController();
 
   void CreateMaximizeModeController();
   void DeleteMaximizeModeController();
 
   void CreateMruWindowTracker();
   void DeleteMruWindowTracker();
 
   void DeleteToastManager();
 
   void SetAcceleratorController(
       std::unique_ptr<AcceleratorController> accelerator_controller);
 
+  // SessionStateObserver:
+  void SessionStateChanged(session_manager::SessionState state) override;
+
  private:
   friend class AcceleratorControllerTest;
   friend class ScopedRootWindowForNewWindows;
   friend class Shell;
   friend class WmShellTestApi;
 
   static WmShell* instance_;
 
   base::ObserverList<ShellObserver> shell_observers_;
   std::unique_ptr<ShellDelegate> delegate_;
@@ skipping 41 matching lines @@
 
 #if defined(OS_CHROMEOS)
   std::unique_ptr<LogoutConfirmationController> logout_confirmation_controller_;
   std::unique_ptr<VpnList> vpn_list_;
 #endif
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_WM_SHELL_H_