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

ash/system/tray_accessibility.cc

 // 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.
 
 #include "ash/system/tray_accessibility.h"
 
 #include "ash/shell.h"
 #include "ash/shell_delegate.h"
 #include "ash/system/tray/system_tray.h"
 #include "ash/system/tray/system_tray_delegate.h"
@@ skipping 209 matching lines @@
 
 TrayAccessibility::TrayAccessibility(SystemTray* system_tray)
     : TrayImageItem(system_tray, IDR_AURA_UBER_TRAY_ACCESSIBILITY),
       default_(NULL),
       detailed_(NULL),
       request_popup_view_(false),
       accessibility_previously_enabled_(IsAnyAccessibilityFeatureEnabled()),
       login_(GetCurrentLoginStatus()) {
   DCHECK(Shell::GetInstance()->delegate());
   DCHECK(system_tray);
-
-  Shell::GetInstance()->AddShellObserver(this);
 }
 
 TrayAccessibility::~TrayAccessibility() {
-  Shell::GetInstance()->RemoveShellObserver(this);
 }
 
 bool TrayAccessibility::GetInitialVisibility() {
   ShellDelegate* delegate = Shell::GetInstance()->delegate();
   // Always shows this on the login screen.
   if (login_ == user::LOGGED_IN_NONE)
     return true;
 
   if (delegate->ShouldAlwaysShowAccessibilityMenu() ||
       IsAnyAccessibilityFeatureEnabled()) {
@@ skipping 33 matching lines @@
 }
 
 void TrayAccessibility::DestroyDefaultView() {
   default_ = NULL;
 }
 
 void TrayAccessibility::DestroyDetailedView() {
   detailed_ = NULL;
 }
 
-void TrayAccessibility::OnLoginStateChanged(user::LoginStatus status) {
+void TrayAccessibility::UpdateAfterLoginStatusChange(user::LoginStatus status) {
   login_ = status;
 
   if (tray_view())
     tray_view()->SetVisible(GetInitialVisibility());
 }
 
 void TrayAccessibility::OnAccessibilityModeChanged() {
   if (tray_view())
     tray_view()->SetVisible(GetInitialVisibility());
 
   bool accessibility_enabled = IsAnyAccessibilityFeatureEnabled();
   if (!accessibility_previously_enabled_ && accessibility_enabled &&
       login_ != user::LOGGED_IN_NONE) {
     // Shows popup if the accessibilty status is being changed to true from
     // false.
     request_popup_view_ = true;
     PopupDetailedView(kTrayPopupAutoCloseDelayForTextInSeconds, false);
   } else if (detailed_) {
     detailed_->GetWidget()->Close();
   }
 
   accessibility_previously_enabled_ = accessibility_enabled;
 }
 
 }  // namespace internal
 }  // namespace ash