Reorder the NativeViews attached to a view via kViewHostKey according to the position of the view

ui/views/widget/native_widget_aura.cc

Index: ui/views/widget/native_widget_aura.cc
diff --git a/ui/views/widget/native_widget_aura.cc b/ui/views/widget/native_widget_aura.cc
index 37a6e41face01420eb0b9c3e499b5e22b8b83a33..87358387578b438f390e38e4ebc06c67228e4d0f 100644
--- a/ui/views/widget/native_widget_aura.cc
+++ b/ui/views/widget/native_widget_aura.cc
@@ -30,11 +30,13 @@
 #include "ui/native_theme/native_theme_aura.h"
 #include "ui/views/drag_utils.h"
 #include "ui/views/ime/input_method_bridge.h"
+#include "ui/views/view_constants_aura.h"
 #include "ui/views/views_delegate.h"
 #include "ui/views/widget/desktop_aura/desktop_native_widget_aura.h"
 #include "ui/views/widget/drop_helper.h"
 #include "ui/views/widget/native_widget_aura_window_observer.h"
 #include "ui/views/widget/native_widget_delegate.h"
+#include "ui/views/widget/native_widget_layer_reorderer_aura.h"
 #include "ui/views/widget/root_view.h"
 #include "ui/views/widget/tooltip_manager_aura.h"
 #include "ui/views/widget/widget_aura_utils.h"
@@ -172,6 +174,9 @@ void NativeWidgetAura::InitNativeWidget(const Widget::InitParams& params) {
                        GetWidget()->widget_delegate()->CanMaximize());
   window_->SetProperty(aura::client::kCanResizeKey,
                        GetWidget()->widget_delegate()->CanResize());
+
+  layer_reorderer_.reset(new NativeWidgetLayerReordererAura(window_,
+      GetWidget()->GetRootView()));
 }
 
 NonClientFrameView* NativeWidgetAura::CreateNonClientFrameView() {
@@ -223,6 +228,10 @@ ui::Layer* NativeWidgetAura::GetLayer() {
   return window_->layer();
 }
 
+void NativeWidgetAura::ReorderLayersForAttachedNativeViews() {
+  layer_reorderer_->ReorderChildWindowLayers();
+}
+
 void NativeWidgetAura::ViewRemoved(View* view) {
   DCHECK(drop_helper_.get() != NULL);
   drop_helper_->ResetTargetViewIfEquals(view);