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

ui/app_list/views/search_box_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 "ui/app_list/views/search_box_view.h"
 
 #include <algorithm>
 
 #include "base/macros.h"
 #include "build/build_config.h"
@@ skipping 154 matching lines @@
   search_box_->SetBackgroundColor(kSearchBoxBackground);
   search_box_->set_placeholder_text_color(kHintTextColor);
   search_box_->set_controller(this);
   search_box_->SetTextInputType(ui::TEXT_INPUT_TYPE_SEARCH);
   search_box_->SetTextInputFlags(ui::TEXT_INPUT_FLAG_AUTOCORRECT_OFF);
   content_container_->AddChildView(search_box_);
   layout->SetFlexForView(search_box_, 1);
 
 #if !defined(OS_CHROMEOS)
   ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
-  menu_button_ = new views::MenuButton(NULL, base::string16(), this, false);
+  menu_button_ = new views::MenuButton(base::string16(), this, false);
   menu_button_->SetBorder(views::Border::NullBorder());
   menu_button_->SetImage(views::Button::STATE_NORMAL,
                          *rb.GetImageSkiaNamed(IDR_APP_LIST_TOOLS_NORMAL));
   menu_button_->SetImage(views::Button::STATE_HOVERED,
                          *rb.GetImageSkiaNamed(IDR_APP_LIST_TOOLS_HOVER));
   menu_button_->SetImage(views::Button::STATE_PRESSED,
                          *rb.GetImageSkiaNamed(IDR_APP_LIST_TOOLS_PRESSED));
   content_container_->AddChildView(menu_button_);
 #endif
 
@@ skipping 278 matching lines @@
   NotifyQueryChanged();
 }
 
 void SearchBoxView::OnSpeechRecognitionStateChanged(
     SpeechRecognitionState new_state) {
   SpeechRecognitionButtonPropChanged();
   SchedulePaint();
 }
 
 }  // namespace app_list