mash: Migrate SessionStateDelegate access to WmShell.

ash/system/chromeos/power/power_event_observer.cc

 // Copyright 2013 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.
 
 #include "ash/system/chromeos/power/power_event_observer.h"
 
 #include "ash/common/session/session_state_delegate.h"
 #include "ash/common/system/tray/system_tray_notifier.h"
 #include "ash/common/wm_shell.h"
 #include "ash/shell.h"
@@ skipping 59 matching lines @@
     screen_lock_callback_.Reset();
   }
 }
 
 void PowerEventObserver::BrightnessChanged(int level, bool user_initiated) {
   Shell::GetInstance()->power_button_controller()->OnScreenBrightnessChanged(
       static_cast<double>(level));
 }
 
 void PowerEventObserver::SuspendImminent() {
-  Shell* shell = Shell::GetInstance();
-  SessionStateDelegate* delegate = shell->session_state_delegate();
+  SessionStateDelegate* delegate = WmShell::Get()->GetSessionStateDelegate();
 
   // This class is responsible for disabling all rendering requests at suspend
   // time and then enabling them at resume time.  When the
   // lock-before-suspending pref is not set this is easy to do since
   // StopRenderingRequests() is just called directly from this function.  If the
   // lock-before-suspending pref _is_ set, then the suspend needs to be delayed
   // until the lock screen is fully visible.  While it is sufficient from a
   // security perspective to block only until the lock screen is ready, which
   // guarantees that the contents of the user's screen are no longer visible,
   // this leads to poor UX on the first resume since neither the user pod nor
@@ skipping 21 matching lines @@
     screen_lock_callback_ = chromeos::DBusThreadManager::Get()
                                 ->GetPowerManagerClient()
                                 ->GetSuspendReadinessCallback();
   } else {
     // The lock-before-suspending pref is not set or the screen has already been
     // locked and the animations have completed.  Rendering can be stopped now.
     StopRenderingRequests();
   }
 
   ui::UserActivityDetector::Get()->OnDisplayPowerChanging();
-  shell->display_configurator()->SuspendDisplays(base::Bind(
+  Shell::GetInstance()->display_configurator()->SuspendDisplays(base::Bind(
       &OnSuspendDisplaysCompleted, chromeos::DBusThreadManager::Get()
                                        ->GetPowerManagerClient()
                                        ->GetSuspendReadinessCallback()));
 }
 
 void PowerEventObserver::SuspendDone(const base::TimeDelta& sleep_duration) {
   Shell::GetInstance()->display_configurator()->ResumeDisplays();
   WmShell::Get()->system_tray_notifier()->NotifyRefreshClock();
 
   // If the suspend request was being blocked while waiting for the lock
@@ skipping 16 matching lines @@
   } else {
     VLOG(1) << "Screen locked without suspend";
   }
 }
 
 void PowerEventObserver::ScreenIsUnlocked() {
   screen_locked_ = false;
 }
 
 }  // namespace ash