Implement all system menu title row buttons for Ash MD

ash/common/system/tray/tray_utils.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/common/system/tray/tray_utils.h"
 
 #include "ash/common/material_design/material_design_controller.h"
+#include "ash/common/session/session_state_delegate.h"
 #include "ash/common/shelf/wm_shelf_util.h"
 #include "ash/common/system/tray/tray_constants.h"
 #include "ash/common/system/tray/tray_item_view.h"
+#include "ash/common/wm_shell.h"
 #include "ui/accessibility/ax_view_state.h"
 #include "ui/gfx/font_list.h"
 #include "ui/gfx/geometry/vector2d.h"
 #include "ui/views/border.h"
 #include "ui/views/controls/label.h"
 
 namespace ash {
 
 void SetupLabelForTray(views::Label* label) {
   if (MaterialDesignController::IsShelfMaterial()) {
@@ skipping 58 matching lines @@
 
   // Do not descend into static text labels which may compute their own labels
   // recursively.
   if (temp_state.role == ui::AX_ROLE_STATIC_TEXT)
     return;
 
   for (int i = 0; i < view->child_count(); ++i)
     GetAccessibleLabelFromDescendantViews(view->child_at(i), out_labels);
 }
 
+bool CanOpenWebUISettings(LoginStatus status) {

[bruthig, 2016/10/19 15:43:09]

It seems kind of odd that we query the TrayUtils to determine if the settings
can be shown but then ask specific delegates owned by the WmShell to actually
show the settings.  I think it would make more sense to ask each of these
delegates (or the WmShell), "CanShowSettings()" and if true, then
"ShowSettings()".

[tdanderson, 2016/10/19 19:49:31]

Added a corresponding TODO.

[bruthig, 2016/10/19 20:17:58]

Acknowledged.

+  return status != LoginStatus::NOT_LOGGED_IN &&
+         status != LoginStatus::LOCKED &&
+         !WmShell::Get()->GetSessionStateDelegate()->IsInSecondaryLoginScreen();
+}
+
 }  // namespace ash