Clean up dns prefetch code, and also port it.

chrome/browser/net/dns_global.cc

 // Copyright (c) 2006-2008 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/dns_global.h"
 
 #include <map>
 #include <string>
 
 #include "base/stats_counters.h"
@@ skipping 364 matching lines @@
 // can ensure its deletion.
 static PrefetchObserver dns_resolution_observer;
 
 void InitDnsPrefetch(PrefService* user_prefs) {
   // Use a large shutdown time so that UI tests (that instigate lookups, and
   // then try to shutdown the browser) don't instigate the CHECK about
   // "some slaves have not finished"
   const TimeDelta kAllowableShutdownTime(TimeDelta::FromSeconds(10));
   DCHECK(NULL == dns_master);
   if (!dns_master) {
-    dns_master = new DnsMaster(kAllowableShutdownTime);
+    dns_master = new DnsMaster();
     // We did the initialization, so we should prime the pump, and set up
     // the DNS resolution system to run.
     off_the_record_observer.Register();
 
     if (user_prefs) {
       bool enabled = user_prefs->GetBoolean(prefs::kDnsPrefetchingEnabled);
       EnableDnsPrefetch(enabled);
     }
 
     DLOG(INFO) << "DNS Prefetch service started";
 
     // Start observing real HTTP stack resolutions.
     net::AddDnsResolutionObserver(&dns_resolution_observer);
   }
 }
 
 void ShutdownDnsPrefetch() {
   DCHECK(NULL != dns_master);
-  DnsMaster* master = dns_master;
+  dns_master->Shutdown();
+}
+
+void FreeDnsPrefetchResources() {
+  DCHECK(NULL != dns_master);
+  delete dns_master;
   dns_master = NULL;
-  if (master->ShutdownSlaves()) {
-    delete master;
-  } else {
-    // Leak instance if shutdown problem.
-    DCHECK(0);
-  }
 }
 
 static void DiscardAllPrefetchState() {
   if (!dns_master)
     return;
   dns_master->DiscardAllResults();
 }
 
 //------------------------------------------------------------------------------
 // Functions to handle saving of hostnames from one session to the next, to
@@ skipping 65 matching lines @@
 }
 
 void TrimSubresourceReferrers() {
   if (NULL == dns_master)
     return;
   dns_master->TrimReferrers();
 }
 
 }  // namespace chrome_browser_net