Moves management of transients out of Window

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 c5c93072aaf03ba52bfb03eba9b309960bcdf9cd..6bcd155114724a65aa6b6fb97724ce94551503a4 100644
--- a/ui/views/widget/native_widget_aura.cc
+++ b/ui/views/widget/native_widget_aura.cc
@@ -28,6 +28,7 @@
 #include "ui/gfx/font.h"
 #include "ui/gfx/screen.h"
 #include "ui/native_theme/native_theme_aura.h"
+#include "ui/views/corewm/transient_window_manager.h"
 #include "ui/views/drag_utils.h"
 #include "ui/views/ime/input_method_bridge.h"
 #include "ui/views/views_delegate.h"
@@ -128,10 +129,11 @@ void NativeWidgetAura::InitNativeWidget(const Widget::InitParams& params) {
   gfx::NativeView parent = params.parent;
   gfx::NativeView context = params.context;
   if (!params.child) {
+
     // Set up the transient child before the window is added. This way the
     // LayoutManager knows the window has a transient parent.
     if (parent && parent->type() != aura::client::WINDOW_TYPE_UNKNOWN) {
-      parent->AddTransientChild(window_);
+      corewm::AddTransientChild(parent, window_);
       if (!context)
         context = parent;
       parent = NULL;
@@ -310,9 +312,9 @@ void NativeWidgetAura::CenterWindow(const gfx::Size& size) {
 
   // If |window_|'s transient parent's bounds are big enough to fit it, then we
   // center it with respect to the transient parent.
-  if (window_->transient_parent()) {
-    gfx::Rect transient_parent_rect = window_->transient_parent()->
-        GetBoundsInRootWindow();
+  if (views::corewm::GetTransientParent(window_)) {
+    gfx::Rect transient_parent_rect =
+        views::corewm::GetTransientParent(window_)->GetBoundsInRootWindow();
     transient_parent_rect.Intersect(work_area);
     if (transient_parent_rect.height() >= size.height() &&
         transient_parent_rect.width() >= size.width())
@@ -1082,7 +1084,7 @@ void NativeWidgetPrivate::GetAllChildWidgets(gfx::NativeView native_view,
 void NativeWidgetPrivate::GetAllOwnedWidgets(gfx::NativeView native_view,
                                              Widget::Widgets* owned) {
   const aura::Window::Windows& transient_children =
-      native_view->transient_children();
+      views::corewm::GetTransientChildren(native_view);
   for (aura::Window::Windows::const_iterator i = transient_children.begin();
        i != transient_children.end(); ++i) {
     NativeWidgetPrivate* native_widget = static_cast<NativeWidgetPrivate*>(