[ash-md] Updates slider control to show thumb highlight when focused

ash/common/system/tray/tray_popup_utils.cc

Index: ash/common/system/tray/tray_popup_utils.cc
diff --git a/ash/common/system/tray/tray_popup_utils.cc b/ash/common/system/tray/tray_popup_utils.cc
index 20e0db8adbcc394536a888548455874e5a381f1d..2abe1f65a88613ba200b6e66e90704a931aa3d2b 100644
--- a/ash/common/system/tray/tray_popup_utils.cc
+++ b/ash/common/system/tray/tray_popup_utils.cc
@@ -270,8 +270,6 @@ views::ToggleButton* TrayPopupUtils::CreateToggleButton(
       (kTrayToggleButtonWidth - toggle_size.width()) / 2;
   toggle->SetBorder(views::CreateEmptyBorder(
       gfx::Insets(vertical_padding, horizontal_padding)));
-  // TODO(varkha): remove this and implement toggle-button specific focus. See
-  // crbug.com/669124
   toggle->SetFocusPainter(CreateFocusPainter());
   toggle->SetAccessibleName(l10n_util::GetStringUTF16(accessible_name_id));
   return toggle;