HostResolver supports optional CNAME lookups.

chrome/test/unit/chrome_test_suite.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.
 
 #ifndef CHROME_TEST_UNIT_CHROME_TEST_SUITE_H_
 #define CHROME_TEST_UNIT_CHROME_TEST_SUITE_H_
 
 #include <string>
 
 #include "build/build_config.h"
@@ skipping 41 matching lines @@
 
 // In many cases it may be not obvious that a test makes a real DNS lookup.
 // We generally don't want to rely on external DNS servers for our tests,
 // so this host resolver procedure catches external queries.
 class WarningHostResolverProc : public net::HostResolverProc {
  public:
   WarningHostResolverProc() : HostResolverProc(NULL) {}
 
   virtual int Resolve(const std::string& host,
                       net::AddressFamily address_family,
+                      net::HostResolverFlags host_resolver_flags,
                       net::AddressList* addrlist) {
     const char* kLocalHostNames[] = {"localhost", "127.0.0.1"};
     bool local = false;
 
     if (host == net::GetHostName()) {
       local = true;
     } else {
       for (size_t i = 0; i < arraysize(kLocalHostNames); i++)
         if (host == kLocalHostNames[i]) {
           local = true;
           break;
         }
     }
 
     // Make the test fail so it's harder to ignore.
     // If you really need to make real DNS query, use
     // net::RuleBasedHostResolverProc and its AllowDirectLookup method.
     EXPECT_TRUE(local) << "Making external DNS lookup of " << host;
 
-    return ResolveUsingPrevious(host, address_family, addrlist);
+    return ResolveUsingPrevious(host, address_family, host_resolver_flags,
+                                addrlist);
   }
 };
 
 class ChromeTestSuite : public TestSuite {
  public:
   ChromeTestSuite(int argc, char** argv)
       : TestSuite(argc, argv),
         stats_table_(NULL) {
   }
 
@@ skipping 90 matching lines @@
 
   // Alternative path to browser binaries.
   FilePath browser_dir_;
 
   ScopedOleInitializer ole_initializer_;
   scoped_refptr<WarningHostResolverProc> host_resolver_proc_;
   net::ScopedDefaultHostResolverProc scoped_host_resolver_proc_;
 };
 
 #endif  // CHROME_TEST_UNIT_CHROME_TEST_SUITE_H_