Call ShowRootWindow on NativeWindow's RootWindow to display the window.

content/shell/shell_stacking_client_ash.cc

 // Copyright (c) 2012 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 "content/shell/shell_stacking_client_ash.h"
 
 #include "ui/aura/client/default_capture_client.h"
 #include "ui/aura/focus_manager.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/test/test_activation_client.h"
 #include "ui/views/corewm/compound_event_filter.h"
 #include "ui/views/corewm/input_method_event_filter.h"
 
 namespace content {
 
-ShellStackingClientAsh::ShellStackingClientAsh() {
+ShellStackingClientAsh::ShellStackingClientAsh(aura::RootWindow* root_window)
+    : root_window_(root_window){
 }
 
 ShellStackingClientAsh::~ShellStackingClientAsh() {
   if (root_window_.get())
     root_window_event_filter_->RemoveHandler(input_method_filter_.get());
 
   aura::client::SetStackingClient(NULL);
 }
 
 aura::Window* ShellStackingClientAsh::GetDefaultParent(
     aura::Window* context,
     aura::Window* window,
     const gfx::Rect& bounds) {
-  if (!root_window_.get()) {
-    root_window_.reset(new aura::RootWindow(
-        aura::RootWindow::CreateParams(gfx::Rect(100, 100))));
-    root_window_->Init();
+  if (!focus_client_.get()) {

[sky, 2013/01/15 21:53:49]

Can we instead have an Init() method that does this so that GetDefaultParent()
doesn't have to always check this?

[Nayan, 2013/01/15 23:39:03]

Done.

     focus_client_.reset(new aura::FocusManager);
     aura::client::SetFocusClient(root_window_.get(), focus_client_.get());
+  }
 
+  if (!input_method_filter_.get()) {
     root_window_event_filter_ = new views::corewm::CompoundEventFilter;
     // Pass ownership of the filter to the root_window.
     root_window_->SetEventFilter(root_window_event_filter_);
 
     input_method_filter_.reset(new views::corewm::InputMethodEventFilter(
-                                   root_window_->GetAcceleratedWidget()));
+        root_window_->GetAcceleratedWidget()));
     input_method_filter_->SetInputMethodPropertyInRootWindow(
         root_window_.get());
     root_window_event_filter_->AddHandler(input_method_filter_.get());
+  }
 
+  if (!test_activation_client_.get()) {
     test_activation_client_.reset(
         new aura::test::TestActivationClient(root_window_.get()));
+  }
 
+  if (!capture_client_.get()) {
     capture_client_.reset(
         new aura::client::DefaultCaptureClient(root_window_.get()));
   }
+
   return root_window_.get();
 }
 
 }  // namespace content