Remove old (dead) app list code.

ui/app_list/search_box_model.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/search_box_model.h"
 
 #include <utility>
 
 #include "base/metrics/histogram.h"
 #include "ui/app_list/search_box_model_observer.h"
@@ skipping 15 matching lines @@
 
 SearchBoxModel::SpeechButtonProperty::~SpeechButtonProperty() {
 }
 
 SearchBoxModel::SearchBoxModel() {
 }
 
 SearchBoxModel::~SearchBoxModel() {
 }
 
-void SearchBoxModel::SetIcon(const gfx::ImageSkia& icon) {
-  icon_ = icon;
-  FOR_EACH_OBSERVER(SearchBoxModelObserver, observers_, IconChanged());
-}
-
 void SearchBoxModel::SetSpeechRecognitionButton(
     std::unique_ptr<SearchBoxModel::SpeechButtonProperty> speech_button) {
   speech_button_ = std::move(speech_button);
   FOR_EACH_OBSERVER(SearchBoxModelObserver,
                     observers_,
                     SpeechRecognitionButtonPropChanged());
 }
 
 void SearchBoxModel::SetHintText(const base::string16& hint_text) {
   if (hint_text_ == hint_text)
@@ skipping 36 matching lines @@
 
 void SearchBoxModel::AddObserver(SearchBoxModelObserver* observer) {
   observers_.AddObserver(observer);
 }
 
 void SearchBoxModel::RemoveObserver(SearchBoxModelObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
 }  // namespace app_list