Cleanup desktop NTP metrics recording, part 2

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 <stddef.h>
 
 #include <bitset>
@@ skipping 66 matching lines @@
   // only the impressions for the first source will be logged, leaving the
   // number of impressions for a source slightly out-of-sync with navigations.
   std::bitset<kNumMostVisited> impression_was_logged_;
 
   // True if at least one iframe came from a server-side suggestion.
   bool has_server_side_suggestions_;
 
   // True if at least one iframe came from a client-side suggestion.
   bool has_client_side_suggestions_;
 
-  // Total number of tiles rendered, no matter if it's a thumbnail, a gray tile
-  // or an external tile.
-  size_t number_of_tiles_;
-
   // Whether we have already emitted NTP stats for this web contents.
   bool has_emitted_;
 
   // Are stats being logged during Chrome startup?
   bool during_startup_;
 
   // 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_