Hide Separators when Zero State Reinstall is enabled.

This fixes a UI bug only visible when this flag is on.

Bug: 911427
Change-Id: I31749509a5ba929fc484ae2812180bb2a5749fc1
Reviewed-on: https://chromium-review.googlesource.com/c/1491737
Commit-Queue: Rob Schonberger <robsc@chromium.org>
Reviewed-by: Alex Newcomer <newcomer@chromium.org>
Reviewed-by: Jenny Zhang <jennyz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#636553}

ash/app_list/views/search_result_tile_item_list_view.cc

@@ -123,8 +123,10 @@ int SearchResultTileItemListView::DoUpdate() {
     }
 
     if (i >= display_results.size()) {
-      if (is_play_store_app_search_enabled_)
+      if (is_app_reinstall_recommendation_enabled_ ||
+          is_play_store_app_search_enabled_) {
         separator_views_[i]->SetVisible(false);
+      }
 
       tile_views_[i]->SetResult(nullptr);
       continue;