Count successes of link rel=prefetch

net/url_request/url_request_http_job.cc

 // Copyright (c) 2012 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.
 
 #include "net/url_request/url_request_http_job.h"
 
 #include "base/base_switches.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
@@ skipping 1602 matching lines @@
       UMA_HISTOGRAM_TIMES("Net.HttpJob.TotalTimeCached", total_time);
       if (is_https_google) {
         if (used_quic) {
           UMA_HISTOGRAM_MEDIUM_TIMES("Net.HttpJob.TotalTimeCached.Secure.Quic",
                                      total_time);
         } else {
           UMA_HISTOGRAM_MEDIUM_TIMES(
               "Net.HttpJob.TotalTimeCached.Secure.NotQuic", total_time);
         }
       }
-    } else  {
+      if (response_info_->unused_since_prefetch) {
+        UMA_HISTOGRAM_COUNTS("Net.Prefetch.HitBytes", prefilter_bytes_read());
+      }

[gavinp, 2016/04/25 15:39:05]

Nit: I don't believe you need these braces.

[jkarlin, 2016/04/25 15:46:14]

Done.

+    } else {
       UMA_HISTOGRAM_TIMES("Net.HttpJob.TotalTimeNotCached", total_time);
       if (is_https_google) {
         if (used_quic) {
           UMA_HISTOGRAM_MEDIUM_TIMES(
               "Net.HttpJob.TotalTimeNotCached.Secure.Quic", total_time);
         } else {
           UMA_HISTOGRAM_MEDIUM_TIMES(
               "Net.HttpJob.TotalTimeNotCached.Secure.NotQuic", total_time);
         }
       }
@@ skipping 31 matching lines @@
   return override_response_headers_.get() ?
              override_response_headers_.get() :
              transaction_->GetResponseInfo()->headers.get();
 }
 
 void URLRequestHttpJob::NotifyURLRequestDestroyed() {
   awaiting_callback_ = false;
 }
 
 }  // namespace net