linux: fix regression where opening the page menu would cause a reload

chrome/browser/gtk/menu_gtk.h

 // Copyright (c) 2009 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 CHROME_BROWSER_GTK_MENU_GTK_H_
 #define CHROME_BROWSER_GTK_MENU_GTK_H_
 
 #include <gtk/gtk.h>
 
 #include <string>
@@ skipping 119 matching lines @@
   MenuGtk::Delegate* delegate_;
 
   // For some menu items, we want to show the accelerator, but not actually
   // explicitly handle it. To this end we connect those menu items' accelerators
   // to this group, but don't attach this group to any top level window.
   GtkAccelGroup* dummy_accel_group_;
 
   // gtk_menu_popup() does not appear to take ownership of popup menus, so
   // MenuGtk explicitly manages the lifetime of the menu.
   OwnedWidgetGtk menu_;
+
+  // True when we should ignore "activate" signals.  Used to prevent
+  // menu items from getting activated when we are setting up the
+  // menu.
+  static bool block_activation_;
 };
 
 #endif  // CHROME_BROWSER_GTK_MENU_GTK_H_