[UI Views] Don't allow a ButtonListener and a MenuButtonListener

chrome/browser/ui/views/website_settings/permission_selector_view.cc

 // 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.
 
 #include "chrome/browser/ui/views/website_settings/permission_selector_view.h"
 
 #include "base/i18n/rtl.h"
 #include "base/macros.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/ui/views/website_settings/website_settings_popup_view.h"
@@ skipping 44 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(PermissionMenuButton);
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 // PermissionMenuButton
 ///////////////////////////////////////////////////////////////////////////////
 
 PermissionMenuButton::PermissionMenuButton(const base::string16& text,
                                            PermissionMenuModel* model,
                                            bool show_menu_marker)
-    : MenuButton(NULL, text, this, show_menu_marker),
-      menu_model_(model) {
+    : MenuButton(text, this, show_menu_marker), menu_model_(model) {
   // Update the themed border before the NativeTheme is applied. Usually this
   // happens in a call to LabelButton::OnNativeThemeChanged(). However, if
   // PermissionMenuButton called that from its override, the NativeTheme would
   // be available, and the button would get native GTK styling on Linux.
   UpdateThemedBorder();
 
   is_rtl_display_ =
       base::i18n::RIGHT_TO_LEFT == base::i18n::GetStringDirection(text);
 }
 
@@ skipping 131 matching lines @@
   // Update the menu button text to reflect the new setting.
   menu_button_->SetText(WebsiteSettingsUI::PermissionActionToUIString(
       permission.type, permission.setting, permission.default_setting,
       content_settings::SETTING_SOURCE_USER));
   menu_button_->SizeToPreferredSize();
 
   FOR_EACH_OBSERVER(PermissionSelectorViewObserver,
                     observer_list_,
                     OnPermissionChanged(permission));
 }