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

chrome/common/ntp_logging_events.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_COMMON_NTP_LOGGING_EVENTS_H_
 #define CHROME_COMMON_NTP_LOGGING_EVENTS_H_
 
 // The different types of events that are logged from the NTP.
 enum NTPLoggingEventType {
   // The user moused over an NTP tile or title.
   NTP_MOUSEOVER = 0,
 
   // The page attempted to load a thumbnail image.
   NTP_THUMBNAIL_ATTEMPT = 1,
 
   // There was an error in loading both the thumbnail image and the fallback
   // (if it was provided), resulting in a grey tile.
   NTP_THUMBNAIL_ERROR = 2,
 
   // The page attempted to load a thumbnail URL while a fallback thumbnail was
   // provided.
   NTP_FALLBACK_THUMBNAIL_REQUESTED = 3,
 
   // The primary thumbnail image failed to load and caused us to use the
   // secondary thumbnail as a fallback.
   NTP_FALLBACK_THUMBNAIL_USED = 4,
 
+  // We got a suggestion coming from the server.

[Mathieu, 2013/11/22 19:58:19]

nit: no we

[beaudoin, 2013/11/22 20:09:35]

Done.

+  NTP_SERVER_SIDE_SUGGESTION = 5,
+
   NTP_NUM_EVENT_TYPES
 };
 
 #endif  // CHROME_COMMON_NTP_LOGGING_EVENTS_H_