Stack at top functionality for Aura-based windows

ui/views/widget/desktop_aura/desktop_native_widget_aura.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 "ui/views/widget/desktop_aura/desktop_native_widget_aura.h"
 
 #include "base/bind.h"
 #include "ui/aura/client/activation_client.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/cursor_client.h"
@@ skipping 546 matching lines @@
 
 void DesktopNativeWidgetAura::SetSize(const gfx::Size& size) {
   if (window_)
     desktop_root_window_host_->SetSize(size);
 }
 
 void DesktopNativeWidgetAura::StackAbove(gfx::NativeView native_view) {
 }
 
 void DesktopNativeWidgetAura::StackAtTop() {
+  if (content_window_)
+    desktop_root_window_host_->StackAtTop();
 }
 
 void DesktopNativeWidgetAura::StackBelow(gfx::NativeView native_view) {
 }
 
 void DesktopNativeWidgetAura::SetShape(gfx::NativeRegion shape) {
   if (window_)
     desktop_root_window_host_->SetShape(shape);
 }
 
@@ skipping 447 matching lines @@
 
 ui::EventHandler* DesktopNativeWidgetAura::GetEventHandler() {
   return this;
 }
 
 void DesktopNativeWidgetAura::UpdateWindowTransparency() {
   window_->SetTransparent(ShouldUseNativeFrame());
 }
 
 }  // namespace views