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

ui/views/widget/desktop_aura/desktop_native_widget_aura.cc

Index: ui/views/widget/desktop_aura/desktop_native_widget_aura.cc
diff --git a/ui/views/widget/desktop_aura/desktop_native_widget_aura.cc b/ui/views/widget/desktop_aura/desktop_native_widget_aura.cc
index 9eb0e5c857eb22ee742d8ae3fef43e1f610af82d..d87e3553f1f8de7501faad69625c8e7cb8035748 100644
--- a/ui/views/widget/desktop_aura/desktop_native_widget_aura.cc
+++ b/ui/views/widget/desktop_aura/desktop_native_widget_aura.cc
@@ -33,9 +33,11 @@
 #include "ui/views/drag_utils.h"
 #include "ui/views/ime/input_method.h"
 #include "ui/views/ime/input_method_bridge.h"
+#include "ui/views/view_constants_aura.h"
 #include "ui/views/widget/desktop_aura/desktop_root_window_host.h"
 #include "ui/views/widget/drop_helper.h"
 #include "ui/views/widget/native_widget_aura_window_observer.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.h"
@@ -270,6 +272,9 @@ void DesktopNativeWidgetAura::InitNativeWidget(
   shadow_controller_.reset(
       new corewm::ShadowController(
           aura::client::GetActivationClient(root_window_.get())));
+
+  layer_reorderer_.reset(new NativeWidgetLayerReordererAura(
+      window_, GetWidget()->GetRootView()));
 }
 
 NonClientFrameView* DesktopNativeWidgetAura::CreateNonClientFrameView() {
@@ -319,6 +324,21 @@ gfx::Vector2d DesktopNativeWidgetAura::CalculateOffsetToAncestorWithLayer(
   return gfx::Vector2d();
 }
 
+void DesktopNativeWidgetAura::ReorderLayers() {
+  layer_reorderer_->ReorderLayers();
+}
+
+bool DesktopNativeWidgetAura::HasNativeViewAttachedToViewTree() const {
+  // TODO(pkotwicz): Set the the kHostViewKey property when a
+  // NativeViewHost attaches a NativeView to |window_|.
+  const std::vector<aura::Window*>& child_windows = window_->children();
+  for (size_t i = 0; i < child_windows.size(); ++i) {
+    if (child_windows[i]->GetProperty(kHostViewKey))
+      return true;
+  }
+  return false;
+}
+
 void DesktopNativeWidgetAura::ViewRemoved(View* view) {
 }