Don't show system notifications while the screen is locked.

chromeos/dbus/power_manager_client.h

 // Copyright (c) 2012 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 CHROMEOS_DBUS_POWER_MANAGER_CLIENT_H_
 #define CHROMEOS_DBUS_POWER_MANAGER_CLIENT_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 123 matching lines @@
 
   // Notifies PowerManager that screen lock has been completed.
   virtual void NotifyScreenLockCompleted() = 0;
 
   // Notifies PowerManager that a user unlocked the screen.
   virtual void NotifyScreenUnlockRequested() = 0;
 
   // Notifies PowerManager that screen is unlocked.
   virtual void NotifyScreenUnlockCompleted() = 0;
 
+  // Return whether or not the screen is locked. Implementation should cache
+  // this state so that it can return immediately. Useful for observers that
+  // need to know the current screen lock state when they are added.
+  virtual bool GetIsScreenLocked() = 0;
+
   // Idle management functions:
 
   // Calculates idle time asynchronously, after the idle time request has
   // replied.  It passes the idle time in seconds to |callback|.  If it
   // encounters some error, it passes -1 to |callback|.
   virtual void CalculateIdleTime(const CalculateIdleTimeCallback& callback) = 0;
 
   // Requests notification for Idle at a certain threshold.
   // NOTE: This notification is one shot, once the machine has been idle for
   // threshold time, a notification will be sent and then that request will be
@@ skipping 29 matching lines @@
   // Create() should be used instead.
   PowerManagerClient();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PowerManagerClient);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DBUS_POWER_MANAGER_CLIENT_H_