Add the UMA recording recall of URLRequests preconnected.

chrome/browser/net/preconnect.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 "chrome/browser/net/preconnect.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 49 matching lines @@
   net::HttpRequestInfo request_info;
   request_info.url = url;
   request_info.method = "GET";
   request_info.extra_headers.SetHeader(net::HttpRequestHeaders::kUserAgent,
                                        context->GetUserAgent(url));
 
   net::NetworkDelegate* delegate = context->network_delegate();
   if (delegate->CanEnablePrivacyMode(url, first_party_for_cookies))
     request_info.privacy_mode = net::kPrivacyModeEnabled;
 
+  delegate->NotifyBeforePreconnect(url);
+
   // It almost doesn't matter whether we use net::LOWEST or net::HIGHEST
   // priority here, as we won't make a request, and will surrender the created
   // socket to the pool as soon as we can.  However, we would like to mark the
   // speculative socket as such, and IF we use a net::LOWEST priority, and if
   // a navigation asked for a socket (after us) then it would get our socket,
   // and we'd get its later-arriving socket, which might make us record that
   // the speculation didn't help :-/.  By using net::HIGHEST, we ensure that
   // a socket is given to us if "we asked first" and this allows us to mark it
   // as speculative, and better detect stats (if it gets used).
   // TODO(jar): histogram to see how often we accidentally use a previously-
@@ skipping 27 matching lines @@
 
   // All preconnects should perform EV certificate verification.
   ssl_config.verify_ev_cert = true;
 
   net::HttpStreamFactory* http_stream_factory = session->http_stream_factory();
   http_stream_factory->PreconnectStreams(count, request_info, priority,
                                          ssl_config, ssl_config);
 }
 
 }  // namespace chrome_browser_net