Add a unit test for the BookmarkSuggestionsProvider.

components/ntp_snippets/bookmarks/bookmark_suggestions_provider.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 "components/ntp_snippets/bookmarks/bookmark_suggestions_provider.h"
 
 #include <utility>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 287 matching lines @@
   std::vector<ContentSuggestion> suggestions;
   for (const BookmarkNode* bookmark : bookmarks) {
     ConvertBookmark(*bookmark, &suggestions);
   }
 
   if (suggestions.empty()) {
     end_of_list_last_visit_date_ = threshold_time;
   } else {
     end_of_list_last_visit_date_ = suggestions.back().publish_date();
   }
-
   observer()->OnNewSuggestions(this, provided_category_,
                                std::move(suggestions));
 }
 
 void BookmarkSuggestionsProvider::FetchBookmarks() {
   if (bookmark_model_->loaded()) {
     FetchBookmarksInternal();
   } else {
     fetch_requested_ = true;
   }
 }
 
 void BookmarkSuggestionsProvider::NotifyStatusChanged(
     CategoryStatus new_status) {
   if (category_status_ == new_status) {
     return;
   }
   category_status_ = new_status;
   observer()->OnCategoryStatusChanged(this, provided_category_, new_status);
 }
 
 }  // namespace ntp_snippets