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

chrome/browser/ui/gtk/browser_actions_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_actions_toolbar_gtk.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/i18n/rtl.h"
@@ skipping 462 matching lines @@
   for (ExtensionButtonMap::iterator iter = extension_button_map_.begin();
        iter != extension_button_map_.end(); ++iter) {
     iter->second->UpdateState();
   }
 }
 
 void BrowserActionsToolbarGtk::Observe(NotificationType type,
                                        const NotificationSource& source,
                                        const NotificationDetails& details) {
   DCHECK(NotificationType::BROWSER_THEME_CHANGED == type);
-  if (theme_service_->UsingNativeTheme())
-    gtk_widget_show(separator_);
-  else
-    gtk_widget_hide(separator_);
+  gtk_widget_set_visible(separator_, theme_service_->UsingNativeTheme());
 }
 
 void BrowserActionsToolbarGtk::SetupDrags() {
   GtkTargetEntry drag_target = GetDragTargetEntry();
   gtk_drag_dest_set(button_hbox_.get(), GTK_DEST_DEFAULT_DROP, &drag_target, 1,
                     GDK_ACTION_MOVE);
 
   signals_.Connect(button_hbox_.get(), "drag-motion",
                    G_CALLBACK(OnDragMotionThunk), this);
 }
@@ skipping 62 matching lines @@
 }
 
 void BrowserActionsToolbarGtk::RemoveButtonForExtension(
     const Extension* extension) {
   if (extension_button_map_.erase(extension->id()))
     UpdateVisibility();
   UpdateChevronVisibility();
 }
 
 void BrowserActionsToolbarGtk::UpdateVisibility() {
-  if (button_count() == 0)
-    gtk_widget_hide(widget());
-  else
-    gtk_widget_show(widget());
+  gtk_widget_set_visible(widget(), button_count() != 0);
 }
 
 bool BrowserActionsToolbarGtk::ShouldDisplayBrowserAction(
     const Extension* extension) {
   // Only display incognito-enabled extensions while in incognito mode.
   return (!profile_->IsOffTheRecord() ||
           profile_->GetExtensionService()->IsIncognitoEnabled(extension->id()));
 }
 
 void BrowserActionsToolbarGtk::HidePopup() {
@@ skipping 373 matching lines @@
 
   menu->PopupAsContext(gfx::Point(event->x_root, event->y_root),
                        event->time);
   return TRUE;
 }
 
 void BrowserActionsToolbarGtk::OnButtonShowOrHide(GtkWidget* sender) {
   if (!resize_animation_.is_animating())
     UpdateChevronVisibility();
 }