Adding UMA metric to record the type of suggestion displayed on the NTP's Most Visited section.

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 1b06895b2ec53ce2acb4348c5815c45094f46cbb..54e01d801c491170d946bb71aaf1e19e3ac4d192 100644
--- a/chrome/browser/ui/webui/ntp/ntp_user_data_logger.cc
+++ b/chrome/browser/ui/webui/ntp/ntp_user_data_logger.cc
@@ -10,6 +10,17 @@
 #include "chrome/common/url_constants.h"
 #include "content/public/browser/navigation_details.h"
 
+namespace {
+
+// Used to track if suggestions were issued by the client or the server.
+enum SuggestionsType {
+  CLIENT_SIDE = 0,
+  SERVER_SIDE = 1,
+  SUGGESTIONS_TYPE_COUNT = 2
+};
+
+}  // namespace
+
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(NTPUserDataLogger);
 
 NTPUserDataLogger::~NTPUserDataLogger() {}
@@ -30,10 +41,15 @@ void NTPUserDataLogger::EmitThumbnailErrorRate() {
         GetPercentError(number_of_fallback_thumbnails_used_,
                         number_of_fallback_thumbnails_requested_));
   }
+  UMA_HISTOGRAM_ENUMERATION(
+      "NewTabPage.SuggestionsType",
+      server_side_suggestions_ ? SERVER_SIDE : CLIENT_SIDE,
+      SUGGESTIONS_TYPE_COUNT);
   number_of_thumbnail_attempts_ = 0;
   number_of_thumbnail_errors_ = 0;
   number_of_fallback_thumbnails_requested_ = 0;
   number_of_fallback_thumbnails_used_ = 0;
+  server_side_suggestions_ = false;
 }
 
 void NTPUserDataLogger::EmitMouseoverCount() {
@@ -58,6 +74,9 @@ void NTPUserDataLogger::LogEvent(NTPLoggingEventType event) {
     case NTP_FALLBACK_THUMBNAIL_USED:
       number_of_fallback_thumbnails_used_++;
       break;
+    case NTP_SERVER_SIDE_SUGGESTION:
+      server_side_suggestions_ = true;
+      break;
     default:
       NOTREACHED();
   }
@@ -84,7 +103,8 @@ NTPUserDataLogger::NTPUserDataLogger(content::WebContents* contents)
       number_of_thumbnail_attempts_(0),
       number_of_thumbnail_errors_(0),
       number_of_fallback_thumbnails_requested_(0),
-      number_of_fallback_thumbnails_used_(0) {
+      number_of_fallback_thumbnails_used_(0),
+      server_side_suggestions_(false) {
 }
 
 size_t NTPUserDataLogger::GetPercentError(size_t errors, size_t events) const {