Add time from navigation_start to NTP LogEvent

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

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_NTP_NTP_USER_DATA_LOGGER_H_
 #define CHROME_BROWSER_UI_WEBUI_NTP_NTP_USER_DATA_LOGGER_H_
 
 #include <string>
 
 #include "base/strings/string16.h"
@@ skipping 23 matching lines @@
   // Returns the name of the histogram that should be logged for a navigation
   // to a specified Most Visited |provider|.
   static std::string GetMostVisitedNavigationHistogramNameForProvider(
       const std::string& provider);
 
   // 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 each time an event occurs on the NTP that requires a counter to be
-  // incremented.
-  void LogEvent(NTPLoggingEventType event);
+  // Called when an event occurs on the NTP that requires a counter to be
+  // incremented. The time parameters contains the time when this event occured
+  // since navigation start.
+  void LogEvent(NTPLoggingEventType event, uint64 time);
 
   // Logs an impression on one of the Most Visited tiles by a given provider.
   void LogMostVisitedImpression(int position, const base::string16& provider);
 
   // Logs a navigation on one of the Most Visited tiles by a given provider.
   void LogMostVisitedNavigation(int position, const base::string16& provider);
 
   // content::WebContentsObserver override
   void NavigationEntryCommitted(
       const content::LoadCommittedDetails& load_details) override;
@@ skipping 39 matching lines @@
   // Total number of mouseovers for this NTP session.
   size_t number_of_mouseovers_;
 
   // The URL of this New Tab Page - varies based on NTP version.
   GURL ntp_url_;
 
   DISALLOW_COPY_AND_ASSIGN(NTPUserDataLogger);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_NTP_NTP_USER_DATA_LOGGER_H_