cros: Suspend media sessions on SuspendImminent

ash/system/power/power_event_observer.h

 // 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.
 
 #ifndef ASH_SYSTEM_POWER_POWER_EVENT_OBSERVER_H_
 #define ASH_SYSTEM_POWER_POWER_EVENT_OBSERVER_H_
 
 #include "ash/ash_export.h"
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "chromeos/dbus/power_manager_client.h"
 #include "chromeos/dbus/session_manager_client.h"
 
 namespace ash {
 
 // A class that observes power-management-related events.
 class ASH_EXPORT PowerEventObserver
     : public chromeos::PowerManagerClient::Observer,
       public chromeos::SessionManagerClient::Observer {
  public:
   // This class registers/unregisters itself as an observer in ctor/dtor.
   PowerEventObserver();
   ~PowerEventObserver() override;
 
-  // Called by the WebUIScreenLocker when all the lock screen animations have
-  // completed.  This really should be implemented via an observer but since
-  // ash/ isn't allowed to depend on chrome/ we need to have the
-  // WebUIScreenLocker reach into ash::Shell to make this call.
+  // Called when all the lock screen animations have completed.
   void OnLockAnimationsComplete();
 
   // chromeos::PowerManagerClient::Observer overrides:
   void BrightnessChanged(int level, bool user_initiated) override;
   void SuspendImminent() override;
   void SuspendDone(const base::TimeDelta& sleep_duration) override;
 
   // chromeos::SessionManagerClient::Observer overrides.
   void ScreenIsLocked() override;
   void ScreenIsUnlocked() override;
 
   // Is the screen currently locked?
-  bool screen_locked_;
+  bool screen_locked_ = false;
 
   // Have the lock screen animations completed?
-  bool waiting_for_lock_screen_animations_;
+  bool waiting_for_lock_screen_animations_ = false;
 
   // If set, called when the lock screen animations have completed to confirm
   // that the system is ready to be suspended.
   base::Closure screen_lock_callback_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PowerEventObserver);
 };
 
 }  // namespace chromeos
 
 #endif  // ASH_SYSTEM_POWER_POWER_EVENT_OBSERVER_H_