Make GetRootWindow() return a Window instead of a RootWindow.

ash/accelerators/exit_warning_handler.cc

 // Copyright 2013 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 "ash/accelerators/exit_warning_handler.h"
 
 #include "ash/shell.h"
 #include "ash/shell_delegate.h"
 #include "ash/shell_window_ids.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "grit/ash_strings.h"
-#include "ui/aura/root_window.h"
+#include "ui/aura/window.h"
 #include "ui/base/accessibility/accessible_view_state.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/font.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/layout/fill_layout.h"
 #include "ui/views/view.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/widget/widget_delegate.h"
@@ skipping 133 matching lines @@
                &ExitWarningHandler::TimerAction);
 }
 
 void ExitWarningHandler::CancelTimer() {
   timer_.Stop();
 }
 
 void ExitWarningHandler::Show() {
   if (widget_)
     return;
-  aura::RootWindow* root_window = Shell::GetTargetRootWindow();
+  aura::Window* root_window = Shell::GetTargetRootWindow();
   ExitWarningWidgetDelegateView* delegate = new ExitWarningWidgetDelegateView;
   gfx::Size rs = root_window->bounds().size();
   gfx::Size ps = delegate->GetPreferredSize();
   gfx::Rect bounds((rs.width() - ps.width()) / 2,
                    (rs.height() - ps.height()) / 3,
                    ps.width(), ps.height());
   views::Widget::InitParams params;
   params.type = views::Widget::InitParams::TYPE_POPUP;
   params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
   params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
@@ skipping 13 matching lines @@
   widget_->Show();
 
   delegate->NotifyAccessibilityEvent(ui::AccessibilityTypes::EVENT_ALERT, true);
 }
 
 void ExitWarningHandler::Hide() {
   widget_.reset();
 }
 
 }  // namespace ash