[ash-md] Adjusts layout of lists with sticky header rows to match specs

ash/common/system/tray/tray_popup_utils.cc

 // Copyright 2016 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_popup_utils.h"
 
 #include "ash/common/ash_constants.h"
 #include "ash/common/ash_view_ids.h"
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/session/session_state_delegate.h"
@@ skipping 409 matching lines @@
   separator->SetBorder(views::CreateEmptyBorder(
       kMenuSeparatorVerticalPadding - kSeparatorWidth,
       left_inset
           ? kMenuExtraMarginFromLeftEdge + kMenuButtonSize +
                 kTrayPopupLabelHorizontalPadding
           : 0,
       kMenuSeparatorVerticalPadding, 0));
   return separator;
 }
 
+views::Separator* TrayPopupUtils::CreateListHeaderSeparator() {
+  views::Separator* separator =
+      new views::Separator(views::Separator::HORIZONTAL);
+  separator->SetColor(kHorizontalSeparatorColor);
+  separator->SetPreferredSize(kSeparatorWidth);
+  separator->SetBorder(views::CreateEmptyBorder(
+      kMenuSeparatorVerticalPadding - kSeparatorWidth, 0, 0, 0));
+  return separator;
+}
+
 bool TrayPopupUtils::CanOpenWebUISettings(LoginStatus status) {
   // TODO(tdanderson): Consider moving this into WmShell, or introduce a
   // CanShowSettings() method in each delegate type that has a
   // ShowSettings() method.
   return status != LoginStatus::NOT_LOGGED_IN &&
          status != LoginStatus::LOCKED &&
          !WmShell::Get()->GetSessionStateDelegate()->IsInSecondaryLoginScreen();
 }
 
 }  // namespace ash