PopularSites: don't wait for a SuggestionsService network request

chrome/browser/android/ntp/most_visited_sites.h

 // Copyright 2013 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 CHROME_BROWSER_ANDROID_NTP_MOST_VISITED_SITES_H_
 #define CHROME_BROWSER_ANDROID_NTP_MOST_VISITED_SITES_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 71 matching lines @@
     Suggestion& operator=(Suggestion&&);
 
    private:
     DISALLOW_COPY_AND_ASSIGN(Suggestion);
   };
 
   explicit MostVisitedSites(Profile* profile);
 
   ~MostVisitedSites() override;
 
-  // Does not take ownership of |observer|, which must outlive this object.
-  void SetMostVisitedURLsObserver(
-      Observer* observer, int num_sites);
+  // Does not take ownership of |observer|, which must outlive this object and
+  // must not be null.

[Bernhard Bauer, 2016/04/29 14:15:31]

From a general API POV, this seems a bit problematic, because if the observer
should be destroyed before this object is, it couldn't be unregistered. We can
deal with that if and when it should arise though.

[Marc Treib, 2016/04/29 14:18:57]

True, but I'm really just documenting the pre-existing assumption here.

+  void SetMostVisitedURLsObserver(Observer* observer, int num_sites);
 
   using ThumbnailCallback = base::Callback<
       void(bool /* is_local_thumbnail */, const SkBitmap* /* bitmap */)>;
   void GetURLThumbnail(const GURL& url, const ThumbnailCallback& callback);
   void AddOrRemoveBlacklistedUrl(const GURL& url, bool add_url);
   void RecordTileTypeMetrics(const std::vector<int>& tile_types);
   void RecordOpenedMostVisitedItem(int index, int tile_type);
 
   // SupervisedUserServiceObserver implementation.
   void OnURLFilterChanged() override;
 
   static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
 
  private:
   friend class MostVisitedSitesTest;
 
   // TODO(treib): use SuggestionsVector in internal functions. crbug.com/601734
   using SuggestionsPtrVector = std::vector<std::unique_ptr<Suggestion>>;
 
-  void QueryMostVisitedURLs();
+  void BuildCurrentSuggestions();
 
   // Initialize the query to Top Sites. Called if the SuggestionsService is not
   // enabled, or if it returns no data.
   void InitiateTopSitesQuery();
 
   // If there's a whitelist entry point for the URL, return the large icon path.
   base::FilePath GetWhitelistLargeIconPath(const GURL& url);
 
   // Callback for when data is available from TopSites.
   void OnMostVisitedURLsAvailable(
@@ skipping 119 matching lines @@
 
   SuggestionsVector current_suggestions_;
 
   // For callbacks may be run after destruction.
   base::WeakPtrFactory<MostVisitedSites> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MostVisitedSites);
 };
 
 #endif  // CHROME_BROWSER_ANDROID_NTP_MOST_VISITED_SITES_H_