MostVisitedSites: simplify prefs

components/ntp_tiles/pref_names.cc

Index: components/ntp_tiles/pref_names.cc
diff --git a/components/ntp_tiles/pref_names.cc b/components/ntp_tiles/pref_names.cc
index dd72edbf8f66cd77b75a7887e7955902781ad838..77c47d0551704575d363b748c3fd6bdd4a6e7ccb 100644
--- a/components/ntp_tiles/pref_names.cc
+++ b/components/ntp_tiles/pref_names.cc
@@ -7,12 +7,13 @@
 namespace ntp_tiles {
 namespace prefs {
 
-// Ordered list of website suggestions shown on the new tab page that will allow
-// retaining the order even if the suggestions change over time.
-const char kNTPSuggestionsURL[] = "ntp.suggestions_url";
+const char kDeprecatedNTPSuggestionsURL[] = "ntp.suggestions_url";
+const char kDeprecatedNTPSuggestionsIsPersonal[] =
+    "ntp.suggestions_is_personal";
 
-// Whether the suggestion was derived from personal data.
-const char kNTPSuggestionsIsPersonal[] = "ntp.suggestions_is_personal";
+// The number of personal suggestions we had previously. Used to figure out
+// whether we need popular sites.
+const char kNumPersonalSuggestions[] = "ntp.num_personal_suggestions";
 
 // If set, overrides the URL for popular sites, including the individual
 // overrides for country and version below.