Use EnablePlayStoreAppSearch feature flag.

ui/app_list/views/search_result_tile_item_list_view.h

 // Copyright 2014 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.
 
 #ifndef UI_APP_LIST_VIEWS_SEARCH_RESULT_TILE_ITEM_LIST_VIEW_H_
 #define UI_APP_LIST_VIEWS_SEARCH_RESULT_TILE_ITEM_LIST_VIEW_H_
 
 #include <vector>
 
 #include "base/macros.h"
@@ skipping 30 matching lines @@
   // Overridden from SearchResultContainerView:
   int DoUpdate() override;
   void UpdateSelectedIndex(int old_selected, int new_selected) override;
 
   std::vector<SearchResultTileItemView*> tile_views_;
 
   std::vector<views::Separator*> separator_views_;
 
   views::Textfield* search_box_;  // Owned by the views hierarchy.
 
-  // Whether the fullscreen app list feature is enabled.
-  const bool is_fullscreen_app_list_enabled_;
+  // Whether the Play Store app search feature is enabled.
+  const bool is_play_store_app_search_enabled_;
 
   DISALLOW_COPY_AND_ASSIGN(SearchResultTileItemListView);
 };
 
 }  // namespace app_list
 
 #endif  // UI_APP_LIST_VIEWS_SEARCH_RESULT_TILE_ITEM_LIST_VIEW_H_