ntp_tiles::metrics: Add rappor metrics for impression URLs per icon type.

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

Index: chrome/browser/ui/webui/ntp/ntp_user_data_logger.cc
diff --git a/chrome/browser/ui/webui/ntp/ntp_user_data_logger.cc b/chrome/browser/ui/webui/ntp/ntp_user_data_logger.cc
index fcb0b593c80105251cb016d131d78c7d92d403a8..12018e3470be1689393b1428f8ea9a479eb7df3f 100644
--- a/chrome/browser/ui/webui/ntp/ntp_user_data_logger.cc
+++ b/chrome/browser/ui/webui/ntp/ntp_user_data_logger.cc
@@ -9,6 +9,7 @@
 
 #include "base/metrics/histogram_macros.h"
 #include "chrome/browser/after_startup_task_utils.h"
+#include "chrome/browser/browser_process.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/search/search.h"
 #include "chrome/browser/sync/profile_sync_service_factory.h"
@@ -155,9 +156,7 @@ void NTPUserDataLogger::EmitNtpStatistics(base::TimeDelta load_time) {
   DVLOG(1) << "Emitting NTP load time: " << load_time << ", "
            << "number of tiles: " << impression_was_logged_.count();
 
-  std::vector<std::pair<ntp_tiles::NTPTileSource,
-                        ntp_tiles::metrics::MostVisitedTileType>>
-      tiles;
+  std::vector<ntp_tiles::metrics::TileImpression> tiles;
   bool has_server_side_suggestions = false;
   for (int i = 0; i < kNumMostVisited; i++) {
     if (!impression_was_logged_[i]) {
@@ -167,10 +166,14 @@ void NTPUserDataLogger::EmitNtpStatistics(base::TimeDelta load_time) {
         ntp_tiles::NTPTileSource::SUGGESTIONS_SERVICE) {
       has_server_side_suggestions = true;
     }
-    tiles.emplace_back(impression_tile_source_[i],
-                       ntp_tiles::metrics::THUMBNAIL);
+    // No URL passed since we're not interested in favicon-related Rappor
+    // metrics.
+    tiles.push_back(
+        {impression_tile_source_[i], ntp_tiles::metrics::THUMBNAIL});
   }
-  ntp_tiles::metrics::RecordPageImpression(tiles);
+
+  // Not interested in Rappor metrics.
+  ntp_tiles::metrics::RecordPageImpression(tiles, /*rappor_service=*/nullptr);
 
   LogLoadTimeHistogram("NewTabPage.LoadTime", load_time);