Most visited iframe now postMessage to signal the iframing page that the link has been displayed

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 5ca5f40b459893973c14c370dc0310bb262f1ac3..fc0923a522a84be1fb784d2d57c65a7d990b4979 100644
--- a/chrome/browser/ui/webui/ntp/ntp_user_data_logger.h
+++ b/chrome/browser/ui/webui/ntp/ntp_user_data_logger.h
@@ -23,11 +23,6 @@ class NTPUserDataLogger
   static NTPUserDataLogger* GetOrCreateFromWebContents(
       content::WebContents* content);
 
-  // Logs the error percentage rate when loading thumbnail images for this NTP
-  // session to UMA histogram. Called when the user navigates to a URL. Only
-  // called for the instant NTP.
-  void EmitThumbnailErrorRate();
-
   // 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.
@@ -47,39 +42,43 @@ class NTPUserDataLogger
  protected:
   explicit NTPUserDataLogger(content::WebContents* contents);
 
-  // Returns the percent error given |events| occurrences and |errors| errors.
-  virtual size_t GetPercentError(size_t errors, size_t events) const;
-
  private:
   friend class content::WebContentsUserData<NTPUserDataLogger>;
 
-  // Total number of mouseovers for this NTP session.
-  size_t number_of_mouseovers_;
+  // True if at least one iframe came from a server-side suggestion. In
+  // practice, either all the iframes are server-side suggestions or none are.
+  bool has_server_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_;
+
+  // Total number of tiles using a local thumbnail image for this NTP session.
+  size_t number_of_thumbnail_tiles_;
 
-  // Total number of attempts made to load thumbnail images for this NTP
-  // session.
-  size_t number_of_thumbnail_attempts_;
+  // Total number of tiles for which no thumbnail is specified and a gray tile
+  // with the domain is used as the main tile.
+  size_t number_of_gray_tiles_;
+
+  // Total number of tiles for which the visual appearance is handled externally
+  // by the page itself.
+  size_t number_of_external_tiles_;
 
   // Total number of errors that occurred when trying to load thumbnail images
   // for this NTP session. When these errors occur a grey tile is shown instead
   // of a thumbnail image.
   size_t number_of_thumbnail_errors_;
 
-  // Total number of attempts made to load thumbnail images while providing a
-  // fallback thumbnail for this NTP session.
-  size_t number_of_fallback_thumbnails_requested_;
-
-  // Total number of errors that occurred while trying to load the primary
-  // thumbnail image and that caused a fallback to the secondary thumbnail.
-  size_t number_of_fallback_thumbnails_used_;
+  // The number of times a gray tile with the domain was used as the fallback
+  // for a failed thumbnail.
+  size_t number_of_gray_tile_fallbacks_;
 
-  // Total number of tiles for which the visual appearance is handled externally
-  // by the page itself.
-  size_t number_of_external_tiles_;
+  // The number of times an external tile, for which the visual appearance is
+  // handled by the page itself, was the fallback for a failed thumbnail.
+  size_t number_of_external_tile_fallbacks_;
 
-  // True if at least one iframe came from a server-side suggestion. In
-  // practice, either all the iframes are server-side suggestions or none are.
-  bool server_side_suggestions_;
+  // 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_;