Don't create MostVisitedSites in incognito

chrome/browser/ntp_tiles/chrome_most_visited_sites_factory.cc

Index: chrome/browser/ntp_tiles/chrome_most_visited_sites_factory.cc
diff --git a/chrome/browser/ntp_tiles/chrome_most_visited_sites_factory.cc b/chrome/browser/ntp_tiles/chrome_most_visited_sites_factory.cc
index 4122c37980868b7305f9dfa24ba1da5a1aac6925..ffa827262cbb9da21404ea8e88370f5fe37d9bec 100644
--- a/chrome/browser/ntp_tiles/chrome_most_visited_sites_factory.cc
+++ b/chrome/browser/ntp_tiles/chrome_most_visited_sites_factory.cc
@@ -108,6 +108,11 @@ void SupervisorBridge::OnURLFilterChanged() {
 // static
 std::unique_ptr<ntp_tiles::MostVisitedSites>
 ChromeMostVisitedSitesFactory::NewForProfile(Profile* profile) {
+  // MostVisitedSites doesn't exist in incognito profiles.
+  if (profile->IsOffTheRecord()) {
+    return nullptr;
+  }
+
   return base::MakeUnique<ntp_tiles::MostVisitedSites>(
       profile->GetPrefs(), TopSitesFactory::GetForProfile(profile),
       SuggestionsServiceFactory::GetForProfile(profile),