Pass PopularSites ownership to MostVisitedSites.

components/ntp_tiles/most_visited_sites.cc

Index: components/ntp_tiles/most_visited_sites.cc
diff --git a/components/ntp_tiles/most_visited_sites.cc b/components/ntp_tiles/most_visited_sites.cc
index 01d16418eb0e01a40fc889e79d39cd713ad43c00..970ee0d0760078ba4d805dedc82336d391c28dc1 100644
--- a/components/ntp_tiles/most_visited_sites.cc
+++ b/components/ntp_tiles/most_visited_sites.cc
@@ -143,12 +143,12 @@ std::string GetSourceHistogramName(int source) {
 MostVisitedSites::MostVisitedSites(PrefService* prefs,
                                    scoped_refptr<history::TopSites> top_sites,
                                    SuggestionsService* suggestions,
-                                   PopularSites* popular_sites,
+                                   std::unique_ptr<PopularSites> popular_sites,
                                    MostVisitedSitesSupervisor* supervisor)
     : prefs_(prefs),
       top_sites_(top_sites),
       suggestions_service_(suggestions),
-      popular_sites_(popular_sites),
+      popular_sites_(std::move(popular_sites)),
       supervisor_(supervisor),
       observer_(nullptr),
       num_sites_(0),