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

chrome/browser/ui/views/content_setting_bubble_contents.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/content_setting_bubble_contents.h"
 
 #include <algorithm>
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 286 matching lines @@
          i != bubble_content.media_menus.end(); ++i) {
       if (!bubble_content_empty)
         layout->AddPaddingRow(0, views::kRelatedControlVerticalSpacing);
       layout->StartRow(0, kMediaMenuColumnSetId);
 
       views::Label* label =
           new views::Label(base::UTF8ToUTF16(i->second.label));
       label->SetHorizontalAlignment(gfx::ALIGN_LEFT);
 
       views::MenuButton* menu_button = new views::MenuButton(
-          NULL, base::UTF8ToUTF16((i->second.selected_device.name)),
-          this, true);
+          base::UTF8ToUTF16((i->second.selected_device.name)), this, true);
       menu_button->SetStyle(views::Button::STYLE_BUTTON);
       menu_button->SetHorizontalAlignment(gfx::ALIGN_LEFT);
       menu_button->set_animate_on_state_change(false);
 
       MediaMenuParts* menu_view = new MediaMenuParts(i->first);
       menu_view->menu_model.reset(new ContentSettingMediaMenuModel(
           i->first,
           content_setting_bubble_model_.get(),
           base::Bind(&ContentSettingBubbleContents::UpdateMenuLabel,
                      base::Unretained(this))));
@@ skipping 173 matching lines @@
   // Make sure the width is at least kMinMediaMenuButtonWidth. The
   // maximum width will be clamped by kMaxContentsWidth of the view.
   menu_width = std::max(kMinMediaMenuButtonWidth, menu_width + margins);
 
   for (MediaMenuPartsMap::const_iterator i = media_menus_.begin();
        i != media_menus_.end(); ++i) {
     i->first->SetMinSize(gfx::Size(menu_width, 0));
     i->first->SetMaxSize(gfx::Size(menu_width, 0));
   }
 }