GTK: Seal up GSEALs, focusing on GtkSelectionData.

ui/base/gtk/gtk_compat.h

 // 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.
 
 #ifndef UI_BASE_GTK_GTK_COMPAT_H_
 #define UI_BASE_GTK_GTK_COMPAT_H_
 #pragma once
 
 #include <gtk/gtk.h>
 
@@ skipping 31 matching lines @@
     GTK_WIDGET_UNSET_FLAGS(widget, GTK_MAPPED);
 }
 
 inline void gtk_widget_set_realized(GtkWidget* widget,
                                     gboolean realized) {
   if (realized)
     GTK_WIDGET_SET_FLAGS(widget, GTK_REALIZED);
   else
     GTK_WIDGET_UNSET_FLAGS(widget, GTK_REALIZED);
 }
+
+inline void gtk_widget_style_attach(GtkWidget* widget) {
+  widget->style = gtk_style_attach(widget->style, widget->window);
+}
 #endif  // !GTK_CHECK_VERSION(2, 20, 0) || defined(GOOGLE_CHROME_BUILD)
 
 #if !GTK_CHECK_VERSION(2, 22, 0)
 inline gint gdk_visual_get_depth(GdkVisual* visual) {
   return visual->depth;
 }
 
 inline GdkWindow* gtk_button_get_event_window(GtkButton* button) {
   return button->event_window;
 }
@@ skipping 15 matching lines @@
 }
 
 inline int gdk_window_get_width(GdkWindow* window) {
   int width;
   gdk_drawable_get_size(GDK_DRAWABLE(window), &width, NULL);
   return width;
 }
 #endif  // !GTK_CHECK_VERSION(2, 24, 0)
 
 #endif  // UI_BASE_GTK_GTK_COMPAT_H_