Second attempt at moving the StackingClient to a property on the RootWindow.

ui/aura/window.cc

 // Copyright (c) 2011 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/aura/window.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/stl_util.h"
 #include "base/string_util.h"
 #include "ui/aura/client/stacking_client.h"
 #include "ui/aura/event.h"
 #include "ui/aura/event_filter.h"
 #include "ui/aura/layout_manager.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/aura/window_observer.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"
 #include "ui/gfx/screen.h"
 
 namespace aura {
 
+namespace {
+
+Window* GetParentForWindow(Window* window, Window* suggested_parent) {
+  if (suggested_parent)
+    return suggested_parent;
+  if (client::GetStackingClient())
+    return client::GetStackingClient()->GetDefaultParent(window);
+  return RootWindow::GetInstance();
+}
+
+}  // namespace
+
 Window::Window(WindowDelegate* delegate)
     : type_(WINDOW_TYPE_UNKNOWN),
       delegate_(delegate),
       parent_(NULL),
       transient_parent_(NULL),
       id_(-1),
       user_data_(NULL),
       stops_event_propagation_(false),
       ignore_events_(false) {
 }
@@ skipping 109 matching lines @@
 
 void Window::SetCanvas(const SkCanvas& canvas, const gfx::Point& origin) {
   // TODO: figure out how this is going to work when animating the layer. In
   // particular if we're animating the size then the underlying Texture is going
   // to be unhappy if we try to set a texture on a size bigger than the size of
   // the texture.
   layer_->SetCanvas(canvas, origin);
 }
 
 void Window::SetParent(Window* parent) {
-  if (parent)
-    parent->AddChild(this);
-  else if (RootWindow::GetInstance()->stacking_client())
-    RootWindow::GetInstance()->stacking_client()->AddChildToDefaultParent(this);
-  else
-    NOTREACHED();
+  GetParentForWindow(this, parent)->AddChild(this);
 }
 
 void Window::StackChildAtTop(Window* child) {
   if (children_.size() <= 1 || child == children_.back())
     return;  // In the front already.
   StackChildAbove(child, children_.back());
 }
 
 void Window::StackChildAbove(Window* child, Window* other) {
   DCHECK_NE(child, other);
@@ skipping 372 matching lines @@
   if (id_ != -1) {
     char id_buf[10];
     base::snprintf(id_buf, sizeof(id_buf), " %d", id_);
     layer_name.append(id_buf);
   }
   layer()->set_name(layer_name);
 #endif
 }
 
 }  // namespace aura