GTK: Remove most calls to widget->window and replace with accessor.

chrome/browser/ui/window_snapshot/window_snapshot_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/window_snapshot/window_snapshot.h"
 
 #include <gdk/gdkx.h>
 #include <gtk/gtk.h>
 
 #include "base/logging.h"
 #include "ui/base/x/x11_util.h"
 #include "ui/gfx/rect.h"
 
 namespace browser {
 
 static cairo_status_t SnapshotCallback(
     void *closure, const unsigned char *data, unsigned int length) {
   std::vector<unsigned char>* png_representation =
       static_cast<std::vector<unsigned char>*>(closure);
 
   size_t old_size = png_representation->size();
   png_representation->resize(old_size + length);
   memcpy(&(*png_representation)[old_size], data, length);
   return CAIRO_STATUS_SUCCESS;
 }
 
 bool GrabWindowSnapshot(gfx::NativeWindow window_handle,
                         std::vector<unsigned char>* png_representation,
                         const gfx::Rect& snapshot_bounds) {
-  GdkWindow* gdk_window = GTK_WIDGET(window_handle)->window;
+  GdkWindow* gdk_window = gtk_widget_get_window(GTK_WIDGET(window_handle));
   Display* display = GDK_WINDOW_XDISPLAY(gdk_window);
   XID win = GDK_WINDOW_XID(gdk_window);
 
   gfx::Rect window_bounds;
   if (ui::GetWindowRect(win, &window_bounds) == 0) {
     LOG(ERROR) << "Couldn't get window bounds";
     return false;
   }
 
   DCHECK_LE(snapshot_bounds.right(), window_bounds.width());
@@ skipping 23 matching lines @@
     return false;
   }
   cairo_surface_write_to_png_stream(
       surface, SnapshotCallback, png_representation);
   cairo_surface_destroy(surface);
 
   return true;
 }
 
 }  // namespace browser