Make EmitNtpStatistics() private.

chrome/browser/ui/webui/ntp/ntp_user_data_logger.h

Index: chrome/browser/ui/webui/ntp/ntp_user_data_logger.h
diff --git a/chrome/browser/ui/webui/ntp/ntp_user_data_logger.h b/chrome/browser/ui/webui/ntp/ntp_user_data_logger.h
index c3efcc52bd411a8ed005c4b0d6220e4aabba5ebf..7150ce86d9c08b68d1bc4a20adbb49d097220629 100644
--- a/chrome/browser/ui/webui/ntp/ntp_user_data_logger.h
+++ b/chrome/browser/ui/webui/ntp/ntp_user_data_logger.h
@@ -31,11 +31,6 @@ class NTPUserDataLogger
   static NTPUserDataLogger* GetOrCreateFromWebContents(
       content::WebContents* content);
 
-  // Logs a number of statistics regarding the NTP. Called when an NTP tab is
-  // about to be deactivated (be it by switching tabs, losing focus or closing
-  // the tab/shutting down Chrome), or when the user navigates to a URL.
-  void EmitNtpStatistics();
-
   // Called when an event occurs on the NTP that requires a counter to be
   // incremented. |time| is the delta time in ms from navigation start until
   // this event happened.
@@ -51,6 +46,12 @@ class NTPUserDataLogger
   void NavigationEntryCommitted(
       const content::LoadCommittedDetails& load_details) override;
 
+  // Called when the tab is closed. Logs statistics.
+  void TabDeactivated();
+
+  // Called when the set of most visited sites changes. Flushes statistics.
+  void MostVisitedItemsChanged();
+
  protected:
   explicit NTPUserDataLogger(content::WebContents* contents);
 
@@ -61,6 +62,19 @@ class NTPUserDataLogger
                            OnMostVisitedItemsChangedFromServer);
   FRIEND_TEST_ALL_PREFIXES(SearchTabHelperTest,
                            OnMostVisitedItemsChangedFromClient);
+  FRIEND_TEST_ALL_PREFIXES(NTPUserDataLoggerTest,
+                           TestLogging);
+
+  // To clarify at the call site whether we are calling EmitNtpStatistics() for
+  // a good reason (CLOSED, NAVIGATED_AWAY) or a questionable one (MV_CHANGED,
+  // INTERNAL_FLUSH).
+  // TODO(sfiera): remove MV_CHANGED, INTERNAL_FLUSH.
+  enum class EmitReason { CLOSED, NAVIGATED_AWAY, MV_CHANGED, INTERNAL_FLUSH };
+
+  // Logs a number of statistics regarding the NTP. Called when an NTP tab is
+  // about to be deactivated (be it by switching tabs, losing focus or closing
+  // the tab/shutting down Chrome), or when the user navigates to a URL.
+  void EmitNtpStatistics(EmitReason reason);
 
   // True if at least one iframe came from a server-side suggestion.
   bool has_server_side_suggestions_;