GTK: More raw struct access removal, this time focusing on GtkDialog.

chrome/browser/ui/gtk/infobars/infobar_gtk.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 "chrome/browser/ui/gtk/infobars/infobar_gtk.h"
 
 #include "base/debug/trace_event.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/infobars/infobar_tab_helper.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 243 matching lines @@
         PaintInfobarBitsOn(sender, event, this);
   }
 
   return FALSE;
 }
 
 void InfoBarGtk::PlatformSpecificShow(bool animate) {
   gtk_widget_show_all(widget_.get());
   gtk_widget_set_size_request(widget_.get(), -1, bar_height());
 
-  if (bg_box_->window)
-    gdk_window_lower(bg_box_->window);
+  GdkWindow* gdk_window = gtk_widget_get_window(bg_box_);
+  if (gdk_window)
+    gdk_window_lower(gdk_window);
 }
 
 void InfoBarGtk::PlatformSpecificOnCloseSoon() {
   // We must close all menus and prevent any signals from being emitted while
   // we are animating the info bar closed.
   menu_.reset();
   menu_model_.reset();
   signals_.reset();
 }
 
@@ skipping 11 matching lines @@
                          const content::NotificationSource& source,
                          const content::NotificationDetails& details) {
   UpdateBorderColor();
 }
 
 void InfoBarGtk::OnChildSizeRequest(GtkWidget* expanded,
                                     GtkWidget* child,
                                     GtkRequisition* requisition) {
   requisition->height = -1;
 }