change the way windows are parented when their parent is set to NULL.

ui/aura/window.cc

Index: ui/aura/window.cc
===================================================================
--- ui/aura/window.cc	(revision 104542)
+++ ui/aura/window.cc	(working copy)
@@ -8,10 +8,12 @@
 
 #include "base/logging.h"
 #include "ui/aura/desktop.h"
+#include "ui/aura/desktop_delegate.h"
 #include "ui/aura/event.h"
 #include "ui/aura/event_filter.h"
 #include "ui/aura/layout_manager.h"
 #include "ui/aura/window_delegate.h"
+#include "ui/aura/window_types.h"
 #include "ui/base/animation/multi_animation.h"
 #include "ui/gfx/canvas_skia.h"
 #include "ui/gfx/compositor/compositor.h"
@@ -23,7 +25,8 @@
 using internal::RootWindow;
 
 Window::Window(WindowDelegate* delegate)
-    : delegate_(delegate),
+    : type_(kWindowType_Toplevel),
+      delegate_(delegate),
       show_state_(ui::SHOW_STATE_NORMAL),
       parent_(NULL),
       id_(-1),
@@ -68,6 +71,12 @@
   layer_->set_delegate(this);
 }
 
+void Window::SetType(int type) {
+  // Cannot change type after the window is initialized.
+  DCHECK(!layer());
+  type_ = type;
+}
+
 void Window::Show() {
   SetVisible(true);
 }
@@ -126,8 +135,10 @@
 void Window::SetParent(Window* parent) {
   if (parent)
     parent->AddChild(this);
+  else if (Desktop::GetInstance()->delegate())
+    Desktop::GetInstance()->delegate()->AddChildToDefaultParent(this);
   else
-    Desktop::GetInstance()->default_parent()->AddChild(this);
+    NOTREACHED();
 }
 
 void Window::Restore() {
@@ -148,10 +159,14 @@
     SetBounds(gfx::Screen::GetMonitorAreaNearestWindow(this));
 }
 
-bool Window::IsToplevelWindowContainer() const {
-  return false;
+ToplevelWindowContainer* Window::AsToplevelWindowContainer() {
+  return NULL;
 }
 
+const ToplevelWindowContainer* Window::AsToplevelWindowContainer() const {
+  return NULL;
+}
+
 void Window::MoveChildToFront(Window* child) {
   DCHECK_EQ(child->parent(), this);
   const Windows::iterator i(std::find(children_.begin(), children_.end(),
@@ -166,6 +181,10 @@
   child->layer()->parent()->MoveToFront(child->layer());
 }
 
+bool Window::CanActivate() const {
+  return IsVisible() && delegate_ && delegate_->ShouldActivate(NULL);
+}
+
 void Window::AddChild(Window* child) {
   DCHECK(std::find(children_.begin(), children_.end(), child) ==
       children_.end());
@@ -185,11 +204,15 @@
 }
 
 Window* Window::GetChildById(int id) {
+  return const_cast<Window*>(const_cast<const Window*>(this)->GetChildById(id));
+}
+
+const Window* Window::GetChildById(int id) const {
   Windows::const_iterator i;
   for (i = children_.begin(); i != children_.end(); ++i) {
     if ((*i)->id() == id)
       return *i;
-    Window* result = (*i)->GetChildById(id);
+    const Window* result = (*i)->GetChildById(id);
     if (result)
       return result;
   }