HostResolver supports optional CNAME lookups.

net/base/address_list.h

Index: net/base/address_list.h
diff --git a/net/base/address_list.h b/net/base/address_list.h
index b477987df6189037c35f9a2fd4e1f8f583e79539..f0eb0cedf8b70cc115b6523e46d2969f9c4cf953 100644
--- a/net/base/address_list.h
+++ b/net/base/address_list.h
@@ -1,10 +1,12 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// 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_ADDRESS_LIST_H_
 #define NET_BASE_ADDRESS_LIST_H_
 
+#include <string>
+
 #include "base/ref_counted.h"
 
 struct addrinfo;
@@ -46,6 +48,13 @@ class AddressList {
   // a reference to |src|'s data.) Otherwise we will make a copy.
   void SetFrom(const AddressList& src, int port);
 
+  // Gets the canonical name for the address.
+  // If the canonical name exists, |*canonical_name| is filled in with the
+  // value and true is returned. If it does not exist, |*canonical_name| is
+  // not altered and false is returned.
+  // |canonical_name| must be a non-null value.
+  bool GetCanonicalName(std::string* canonical_name) const;
+
   // Clears all data from this address list. This leaves the list in the same
   // empty state as when first constructed.
   void Reset();