Ensure PopularSite icon availability in ntp_tiles.

components/ntp_tiles/most_visited_sites.h

Index: components/ntp_tiles/most_visited_sites.h
diff --git a/components/ntp_tiles/most_visited_sites.h b/components/ntp_tiles/most_visited_sites.h
index b305a4da920654703a3ebc3f1ae425c7e4a89a71..67b8243267628ed06d37ce488e77b879de7690c0 100644
--- a/components/ntp_tiles/most_visited_sites.h
+++ b/components/ntp_tiles/most_visited_sites.h
@@ -34,6 +34,8 @@ class PrefRegistrySyncable;
 
 namespace ntp_tiles {
 
+class IconCacher;
+
 // Shim interface for SupervisedUserService.
 class MostVisitedSitesSupervisor {
  public:
@@ -86,7 +88,8 @@ class MostVisitedSites : public history::TopSitesObserver,
   class Observer {
    public:
     virtual void OnMostVisitedURLsAvailable(const NTPTilesVector& tiles) = 0;
-    virtual void OnPopularURLsAvailable(const PopularSitesVector& sites) {}
+    // TODO(sfiera): make this method required after iOS implements it:
+    virtual void OnIconMadeAvailable(const GURL& site_url) {}
 
    protected:
     virtual ~Observer() {}
@@ -101,6 +104,7 @@ class MostVisitedSites : public history::TopSitesObserver,
                    scoped_refptr<history::TopSites> top_sites,
                    suggestions::SuggestionsService* suggestions,
                    std::unique_ptr<PopularSites> popular_sites,
+                   std::unique_ptr<IconCacher> icon_cacher,
                    MostVisitedSitesSupervisor* supervisor);
 
   ~MostVisitedSites() override;
@@ -162,6 +166,8 @@ class MostVisitedSites : public history::TopSitesObserver,
 
   void OnPopularSitesAvailable(bool success);
 
+  void OnIconMadeAvailable(const GURL& site_url, bool newly_available);
+
   // history::TopSitesObserver implementation.
   void TopSitesLoaded(history::TopSites* top_sites) override;
   void TopSitesChanged(history::TopSites* top_sites,
@@ -171,6 +177,7 @@ class MostVisitedSites : public history::TopSitesObserver,
   scoped_refptr<history::TopSites> top_sites_;
   suggestions::SuggestionsService* suggestions_service_;
   std::unique_ptr<PopularSites> const popular_sites_;
+  std::unique_ptr<IconCacher> const icon_cacher_;
   MostVisitedSitesSupervisor* supervisor_;
 
   Observer* observer_;