Avoid doing concurrent DNS resolves of the same hostname

net/net.gyp

 # Copyright (c) 2009 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'includes': [
     '../build/common.gypi',
@@ skipping 62 matching lines @@
         'base/file_stream_posix.cc',
         'base/file_stream_win.cc',
         'base/filter.cc',
         'base/filter.h',
         'base/force_tls_state.cc',
         'base/force_tls_state.h',
         'base/gzip_filter.cc',
         'base/gzip_filter.h',
         'base/gzip_header.cc',
         'base/gzip_header.h',
+        'base/host_cache.cc',
+        'base/host_cache.h',
         'base/host_resolver.cc',
         'base/host_resolver.h',
         'base/io_buffer.cc',
         'base/io_buffer.h',
         'base/listen_socket.cc',
         'base/listen_socket.h',
         'base/load_flags.h',
         'base/mime_sniffer.cc',
         'base/mime_sniffer.h',
         'base/mime_util.cc',
@@ skipping 294 matching lines @@
       'target_name': 'net_unittests',
       'type': 'executable',
       'dependencies': [
         'net',
         'net_test_support',
         '../base/base.gyp:base',
         '../testing/gtest.gyp:gtest',
       ],
       'msvs_guid': 'E99DA267-BE90-4F45-88A1-6919DB2C7567',
       'sources': [
+        'base/address_list_unittest.cc',
         'base/base64_unittest.cc',
         'base/bzip2_filter_unittest.cc',
         'base/cookie_monster_unittest.cc',
         'base/cookie_policy_unittest.cc',
         'base/data_url_unittest.cc',
         'base/directory_lister_unittest.cc',
         'base/escape_unittest.cc',
         'base/file_stream_unittest.cc',
         'base/filter_unittest.cc',
         'base/filter_unittest.h',
         'base/force_tls_state_unittest.cc',
         'base/gzip_filter_unittest.cc',
+        'base/host_cache_unittest.cc',
         'base/host_resolver_unittest.cc',
         'base/listen_socket_unittest.cc',
         'base/listen_socket_unittest.h',
         'base/mime_sniffer_unittest.cc',
         'base/mime_util_unittest.cc',
         'base/net_util_unittest.cc',
         'base/registry_controlled_domain_unittest.cc',
         'base/run_all_unittests.cc',
         'base/sdch_filter_unittest.cc',
         'base/ssl_client_socket_unittest.cc',
@@ skipping 244 matching lines @@
             'tools/fetch/http_server.cc',
             'tools/fetch/http_server.h',
             'tools/fetch/http_session.cc',
             'tools/fetch/http_session.h',
           ],
         },
       ],
     }],
   ],
 }