Initial support for built-in DNS resolver/cache.

net/base/host_resolver.h

 // Copyright (c) 2010 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 NET_BASE_HOST_RESOLVER_H_
 #define NET_BASE_HOST_RESOLVER_H_
 #pragma once
 
 #include <string>
 
 #include "base/scoped_ptr.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/address_family.h"
 #include "net/base/completion_callback.h"
 #include "net/base/host_port_pair.h"
 #include "net/base/request_priority.h"
 
 namespace net {
 
 class AddressList;
 class BoundNetLog;
 class HostResolverImpl;
+class HostResolverProc;
 class NetLog;
 
 // This class represents the task of resolving hostnames (or IP address
 // literal) to an AddressList object.
 //
 // HostResolver can handle multiple requests at a time, so when cancelling a
 // request the RequestHandle that was returned by Resolve() needs to be
 // given.  A simpler alternative for consumers that only have 1 outstanding
 // request at a time is to create a SingleRequestHostResolver wrapper around
 // HostResolver (which will automatically cancel the single request when it
@@ skipping 190 matching lines @@
   // The current request (if any).
   HostResolver::RequestHandle cur_request_;
   CompletionCallback* cur_request_callback_;
 
   // Completion callback for when request to |resolver_| completes.
   net::CompletionCallbackImpl<SingleRequestHostResolver> callback_;
 
   DISALLOW_COPY_AND_ASSIGN(SingleRequestHostResolver);
 };
 
-// Creates a HostResolver implementation that queries the underlying system.
-// (Except if a unit-test has changed the global HostResolverProc using
-// ScopedHostResolverProc to intercept requests to the system).
-// |max_concurrent_resolves| is how many resolve requests will be allowed to
-// run in parallel. Pass HostResolver::kDefaultParallelism to choose a
-// default value.
+// Creates a HostResolver implementation using |resolver_proc| as resolver,
+// (which if NULL, will default to getaddrinfo() wrapper) that queries the
+// underlying system, |max_concurrent_resolves| is how many resolve
+// requests will be allowed to run in parallel. Pass
+// HostResolver::kDefaultParallelism to choose a default value.
 HostResolver* CreateSystemHostResolver(size_t max_concurrent_resolves,
+                                       HostResolverProc* resolver_proc,
                                        NetLog* net_log);
 
 }  // namespace net
 
 #endif  // NET_BASE_HOST_RESOLVER_H_