Tell DNS prefetch when search URL is likely so that prewarming can be done...

chrome/browser/net/dns_global.h

 // 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.
 
 // This is the global interface for the dns prefetch services.  It centralizes
 // initialization, along with all the callbacks etc. to connect to the browser
 // process.  This allows the more standard DNS prefetching services, such as
 // provided by DnsMaster to be left as more generally usable code, and possibly
 // be shared across multiple client projects.
 
@@ skipping 24 matching lines @@
 void FreeDnsPrefetchResources();
 
 // Creates the HostResolver observer for the prefetching system.
 net::HostResolver::Observer* CreatePrefetchObserver();
 
 //------------------------------------------------------------------------------
 // Global APIs relating to Prefetching in browser
 void EnableDnsPrefetch(bool enable);
 void RegisterPrefs(PrefService* local_state);
 void RegisterUserPrefs(PrefService* user_prefs);
+
 // Renderer bundles up list and sends to this browser API via IPC.
 void DnsPrefetchList(const NameList& hostnames);
+
 // This API is used by the autocomplete popup box (as user types).
-void DnsPrefetchUrl(const GURL& url);
+// Search URL's may be "prewarmed" above and beyond the DNS resolution.
+void DnsPrefetchUrl(const GURL& url, bool is_search_url);
+
+// When displaying info in about:dns, the following API is called.
 void DnsPrefetchGetHtmlInfo(std::string* output);
 
 //------------------------------------------------------------------------------
 void SaveDnsPrefetchStateForNextStartupAndTrim(PrefService* prefs);
 // Helper class to handle global init and shutdown.
 class DnsGlobalInit {
  public:
   // Too many concurrent lookups negate benefits of prefetching by trashing
   // the OS cache before all resource loading is complete.
   // This is the default.
   static const size_t kMaxPrefetchConcurrentLookups;
 
   // When prefetch requests are queued beyond some period of time, then the
   // system is congested, and we need to clear all queued requests to get out
   // of that state.  The following is the suggested default time limit.
   static const int kMaxPrefetchQueueingDelayMs;
 
   DnsGlobalInit(PrefService* user_prefs, PrefService* local_state);
 
  private:
   // Maintain a field trial instance when we do A/B testing.
   scoped_refptr<FieldTrial> trial_;
 
   DISALLOW_COPY_AND_ASSIGN(DnsGlobalInit);
 };
 
 }  // namespace chrome_browser_net
 
 #endif  // CHROME_BROWSER_NET_DNS_GLOBAL_H_