No paint to layer for custom notification close button

ui/message_center/views/custom_notification_view.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 "ui/message_center/views/custom_notification_view.h"
 
 #include <algorithm>
 
 #include "ui/gfx/geometry/size.h"
 #include "ui/message_center/message_center_style.h"
@@ skipping 14 matching lines @@
   AddChildView(contents_view_);
 
   if (contents_view_->background()) {
     background_view()->background()->SetNativeControlColor(
         contents_view_->background()->get_color());
   }
 
   AddChildView(small_image());
 
   CreateOrUpdateCloseButtonView(notification);
-
-  // Use a layer for close button so that custom content does not eclipse it.
-  if (close_button())
-    close_button()->SetPaintToLayer(true);
 }
 
 CustomNotificationView::~CustomNotificationView() {}
 
 void CustomNotificationView::SetDrawBackgroundAsActive(bool active) {
   // Do nothing if |contents_view_| has a background.
   if (contents_view_->background())
     return;
 
   MessageView::SetDrawBackgroundAsActive(active);
@@ skipping 12 matching lines @@
                std::min(kMaxHeight, contents_height + insets.height())));
 }
 
 void CustomNotificationView::Layout() {
   MessageView::Layout();
 
   contents_view_->SetBoundsRect(GetContentsBounds());
 }
 
 }  // namespace message_center