GTK: Now that we depend on gtk 2.18+, replace this pattern:

chrome/browser/ui/gtk/browser_toolbar_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/browser_toolbar_gtk.h"
 
 #include <X11/XF86keysym.h>
 #include <gdk/gdkkeysyms.h>
 #include <gtk/gtk.h>
 
@@ skipping 597 matching lines @@
 
   bool url_is_newtab = url.SchemeIs(chrome::kChromeUIScheme) &&
                        url.host() == chrome::kChromeUINewTabHost;
   home_page_is_new_tab_page_.SetValue(url_is_newtab);
   if (!url_is_newtab)
     home_page_.SetValue(url.spec());
 }
 
 void BrowserToolbarGtk::NotifyPrefChanged(const std::string* pref) {
   if (!pref || *pref == prefs::kShowHomeButton) {
-    if (show_home_button_.GetValue() && !ShouldOnlyShowLocation()) {
-      gtk_widget_show(home_->widget());
-    } else {
-      gtk_widget_hide(home_->widget());
-    }
+    bool visible = show_home_button_.GetValue() && !ShouldOnlyShowLocation();
+    gtk_widget_set_visible(home_->widget(), visible);
   }
 
   if (!pref ||
       *pref == prefs::kHomePage ||
       *pref == prefs::kHomePageIsNewTabPage)
     SetUpDragForHomeButton(!home_page_.IsManaged() &&
                            !home_page_is_new_tab_page_.IsManaged());
 }
 
 bool BrowserToolbarGtk::ShouldOnlyShowLocation() const {
@@ skipping 17 matching lines @@
   int x_offset = base::i18n::IsRTL() ? 0 :
       sender->allocation.width - badge->width();
   int y_offset = 0;
   canvas.DrawBitmapInt(
       *badge,
       sender->allocation.x + x_offset,
       sender->allocation.y + y_offset);
 
   return FALSE;
 }