Remove TrayPopupLabelButton (a pre-MD class) and its assets.

ash/common/system/tray_accessibility.cc

Index: ash/common/system/tray_accessibility.cc
diff --git a/ash/common/system/tray_accessibility.cc b/ash/common/system/tray_accessibility.cc
index 5ec4704668ca11ee0608cd1decc46befbaa426af..9e1fda577e811a2080b97da2577f6183c38fd425 100644
--- a/ash/common/system/tray_accessibility.cc
+++ b/ash/common/system/tray_accessibility.cc
@@ -17,7 +17,6 @@
 #include "ash/common/system/tray/tray_details_view.h"
 #include "ash/common/system/tray/tray_item_more.h"
 #include "ash/common/system/tray/tray_popup_item_style.h"
-#include "ash/common/system/tray/tray_popup_label_button.h"
 #include "ash/common/system/tray/tray_popup_utils.h"
 #include "ash/common/system/tray/tri_view.h"
 #include "ash/common/wm_shell.h"
@@ -236,33 +235,6 @@ void AccessibilityDetailedView::AppendAccessibilityList() {
 
 void AccessibilityDetailedView::AppendHelpEntries() {
   DCHECK(!UseMdMenu());
-  // Currently the help page requires a browser window.
-  // TODO(yoshiki): show this even on login/lock screen. crbug.com/158286
-  if (!TrayPopupUtils::CanOpenWebUISettings(login_))
-    return;
-
-  views::View* bottom_row = new View();
-  views::BoxLayout* layout = new views::BoxLayout(
-      views::BoxLayout::kHorizontal, kTrayMenuBottomRowPadding,
-      kTrayMenuBottomRowPadding, kTrayMenuBottomRowPaddingBetweenItems);
-  layout->SetDefaultFlex(1);
-  bottom_row->SetLayoutManager(layout);
-
-  ui::ResourceBundle& bundle = ui::ResourceBundle::GetSharedInstance();
-
-  TrayPopupLabelButton* help = new TrayPopupLabelButton(
-      this,
-      bundle.GetLocalizedString(IDS_ASH_STATUS_TRAY_ACCESSIBILITY_LEARN_MORE));
-  bottom_row->AddChildView(help);
-  help_view_ = help;
-
-  TrayPopupLabelButton* settings = new TrayPopupLabelButton(
-      this,
-      bundle.GetLocalizedString(IDS_ASH_STATUS_TRAY_ACCESSIBILITY_SETTINGS));
-  bottom_row->AddChildView(settings);
-  settings_view_ = settings;
-
-  AddChildView(bottom_row);
 }
 
 HoverHighlightView* AccessibilityDetailedView::AddScrollListItem(