AddAccessibilityObserver   70 ash/system/chromeos/virtual_keyboard/virtual_keyboard_tray.cc         AddAccessibilityObserver(this);
AddAccessibilityObserver   47 ash/system/tray/system_tray_notifier.h   void AddAccessibilityObserver(AccessibilityObserver* observer);
AddAccessibilityObserver  323 ash/system/tray_accessibility.cc   Shell::GetInstance()->system_tray_notifier()->AddAccessibilityObserver(this);