Remove old (dead) app list code.

ui/app_list/views/search_box_view.h

Index: ui/app_list/views/search_box_view.h
diff --git a/ui/app_list/views/search_box_view.h b/ui/app_list/views/search_box_view.h
index 8abee80181359c172148b7dfa70ee035e9b17b74..4aa6a84400c91726d0ef32ba4b42fd8e0f097050 100644
--- a/ui/app_list/views/search_box_view.h
+++ b/ui/app_list/views/search_box_view.h
@@ -111,7 +111,6 @@ class APP_LIST_EXPORT SearchBoxView : public views::View,
                            const ui::Event* event) override;
 
   // Overridden from SearchBoxModelObserver:
-  void IconChanged() override;
   void SpeechRecognitionButtonPropChanged() override;
   void HintTextChanged() override;
   void SelectionModelChanged() override;
@@ -128,7 +127,6 @@ class APP_LIST_EXPORT SearchBoxView : public views::View,
   std::unique_ptr<AppListMenuViews> menu_;
 
   views::View* content_container_;     // Owned by views hierarchy.
-  views::ImageView* icon_view_;  // Owned by views hierarchy.
   SearchBoxImageButton* back_button_;    // Owned by views hierarchy.
   SearchBoxImageButton* speech_button_;  // Owned by views hierarchy.
   views::MenuButton* menu_button_;  // Owned by views hierarchy.