Reapplies r91761.

chrome/browser/ui/gtk/tabs/tab_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/tabs/tab_gtk.h"
 
 #include <gdk/gdkkeysyms.h>
 
 #include "base/memory/singleton.h"
 #include "base/utf_string_conversions.h"
@@ skipping 218 matching lines @@
 
 bool TabGtk::IsActive() const {
   return delegate_->IsTabActive(this);
 }
 
 bool TabGtk::IsSelected() const {
   return delegate_->IsTabSelected(this);
 }
 
 bool TabGtk::IsVisible() const {
-  return GTK_WIDGET_FLAGS(event_box_) & GTK_VISIBLE;
+  return gtk_widget_get_visible(event_box_);
 }
 
 void TabGtk::SetVisible(bool visible) const {
   gtk_widget_set_visible(event_box_, visible);
 }
 
 void TabGtk::CloseButtonClicked() {
   delegate_->CloseTab(this);
 }
 
@@ skipping 72 matching lines @@
     gdk_event_free(last_mouse_down_);
     last_mouse_down_ = NULL;
   }
 
   // Notify the drag helper that we're done with any potential drag operations.
   // Clean up the drag helper, which is re-created on the next mouse press.
   delegate_->EndDrag(canceled);
 
   observer_.reset();
 }