Enable download home by default

chrome/browser/ntp_snippets/download_suggestions_provider_unittest.cc

 // Copyright 2016 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 "chrome/browser/ntp_snippets/download_suggestions_provider.h"
 
 #include <memory>
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
@@ skipping 267 matching lines @@
   DownloadSuggestionsProvider* CreateProvider(bool show_assets,
                                               bool show_offline_pages) {
     DCHECK(!provider_);
     DCHECK(show_assets || show_offline_pages);
 
     // TODO(crbug.com/681766): Extract DownloadHistory interface and move
     // implementation into DownloadHistoryImpl. Then mock it.
     provider_ = base::MakeUnique<DownloadSuggestionsProvider>(
         &observer_, show_offline_pages ? &offline_pages_model_ : nullptr,
         show_assets ? &downloads_manager_ : nullptr, &download_history_,
-        pref_service(),
-        /*download_manager_ui_enabled=*/false);
+        pref_service());
     return provider_.get();
   }
 
   void DestroyProvider() { provider_.reset(); }
 
   Category downloads_category() {
     return Category::FromKnownCategory(
         ntp_snippets::KnownCategories::DOWNLOADS);
   }
 
@@ skipping 709 matching lines @@
 
   EXPECT_CALL(*observer(), OnNewSuggestions(_, _, _));
 
   downloads_manager()->mutable_items()->clear();
   FireHistoryQueryComplete();
 
   *(downloads_manager()->mutable_items()) = CreateDummyAssetDownloads({1});
   // Once the manager has been loaded, the ids should be pruned.
   EXPECT_THAT(GetDismissedSuggestions(), IsEmpty());
 }