A11y: Add the option to always show the a11y tray menu regardless of the state of a11y features

ash/system/tray_accessibility.h

Index: ash/system/tray_accessibility.h
diff --git a/ash/system/tray_accessibility.h b/ash/system/tray_accessibility.h
index 1ee1aab1ef8f00260c4c7047565bc350480f791e..e0162f5dee9c443babc3cc1f633bb6264c6fda69 100644
--- a/ash/system/tray_accessibility.h
+++ b/ash/system/tray_accessibility.h
@@ -26,8 +26,7 @@ class ASH_EXPORT AccessibilityObserver {
 namespace internal {
 
 class TrayAccessibility : public TrayImageItem,
-                          public AccessibilityObserver,
-                          public ShellObserver {
+                          public AccessibilityObserver {
  public:
   explicit TrayAccessibility(SystemTray* system_tray);
   virtual ~TrayAccessibility();
@@ -39,13 +38,11 @@ class TrayAccessibility : public TrayImageItem,
   virtual views::View* CreateDetailedView(user::LoginStatus status) OVERRIDE;
   virtual void DestroyDefaultView() OVERRIDE;
   virtual void DestroyDetailedView() OVERRIDE;
+  virtual void UpdateAfterLoginStatusChange(user::LoginStatus status) OVERRIDE;
 
   // Overridden from AccessibilityObserver.
   virtual void OnAccessibilityModeChanged() OVERRIDE;
 
-  // Overriden from ShellObserver.
-  virtual void OnLoginStateChanged(user::LoginStatus status) OVERRIDE;
-
   views::View* default_;
   views::View* detailed_;