Add ContextualSuggestionsService to Omnibox

components/omnibox/browser/zero_suggest_provider.h

 // Copyright (c) 2012 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.
 //
 // This file contains the zero-suggest autocomplete provider. This experimental
 // provider is invoked when the user focuses in the omnibox prior to editing,
 // and generates search query suggestions based on the current URL.
 
 #ifndef COMPONENTS_OMNIBOX_BROWSER_ZERO_SUGGEST_PROVIDER_H_
 #define COMPONENTS_OMNIBOX_BROWSER_ZERO_SUGGEST_PROVIDER_H_
@@ skipping 80 matching lines @@
   // Adds AutocompleteMatches for each of the suggestions in |results| to
   // |map|.
   void AddSuggestResultsToMap(
       const SearchSuggestionParser::SuggestResults& results,
       MatchMap* map);
 
   // Returns an AutocompleteMatch for a navigational suggestion |navigation|.
   AutocompleteMatch NavigationToMatch(
       const SearchSuggestionParser::NavigationResult& navigation);
 
-  // Fetches zero-suggest suggestions by sending a request using |suggest_url|.
-  void Run(const GURL& suggest_url);
-
   // Converts the parsed results to a set of AutocompleteMatches and adds them
   // to |matches_|.  Also update the histograms for how many results were
   // received.
   void ConvertResultsToAutocompleteMatches();
 
   // Returns an AutocompleteMatch for the current URL. The match should be in
   // the top position so that pressing enter has the effect of reloading the
   // page.
   AutocompleteMatch MatchForCurrentURL();
 
   // When the user is in the Most Visited field trial, we ask the TopSites
   // service for the most visited URLs during Run().  It calls back to this

[Mark P, 2017/07/18 19:11:30]

Please revise, as Run() doesn't exist anymore.

   // function to return those |urls|.
   void OnMostVisitedUrlsAvailable(const history::MostVisitedURLList& urls);
 
+  void OnContextualSuggestionsFetcherAvailable(

[Mark P, 2017/07/18 19:11:30]

Please comment.

+      std::unique_ptr<net::URLFetcher> fetcher);
+
   // Whether we can show zero suggest suggestions that are not based on
   // |current_page_url|. Also checks that other conditions for non-contextual
   // zero suggest are satisfied.
   bool ShouldShowNonContextualZeroSuggest(const GURL& current_page_url) const;
 
   // Returns a URL string that should be used to to request contextual
   // suggestions from the default provider.  Does not take into account whether
   // sending this request is prohibited (e.g., in an incognito window).  Returns
   // an empty string in case of an error.
   std::string GetContextualSuggestionsUrl() const;
@@ skipping 38 matching lines @@
   // Whether we are waiting for a most visited visited urls callback to run.
   bool waiting_for_most_visited_urls_request_;
 
   // For callbacks that may be run after destruction.
   base::WeakPtrFactory<ZeroSuggestProvider> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ZeroSuggestProvider);
 };
 
 #endif  // COMPONENTS_OMNIBOX_BROWSER_ZERO_SUGGEST_PROVIDER_H_