Extracts CT DNS test utilities into a standalone class

components/certificate_transparency.gypi

 # Copyright 2015 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.
 
 {
   'targets': [
     {
       # GN version: //components/certificate_transparency
       'target_name': 'certificate_transparency',
       'type': 'static_library',
@@ skipping 17 matching lines @@
         'certificate_transparency/log_dns_client.cc',
         'certificate_transparency/log_proof_fetcher.h',
         'certificate_transparency/log_proof_fetcher.cc',
         'certificate_transparency/pref_names.cc',
         'certificate_transparency/pref_names.h',
         'certificate_transparency/single_tree_tracker.cc',
         'certificate_transparency/single_tree_tracker.h',
         'certificate_transparency/tree_state_tracker.h',
         'certificate_transparency/tree_state_tracker.cc',
       ],
-    }
+    },
+    {
+      # GN version: //components/certificate_transparency:test_support
+      'target_name': 'certificate_transparency_test_support',
+      'type': 'static_library',
+      'include_dirs': [
+        '..',
+      ],
+      'dependencies': [
+        '../base/base.gyp:base',
+        '../net/net.gyp:net',
+        '../net/net.gyp:net_test_support',
+        '../testing/gtest.gyp:gtest',
+      ],
+      'sources': [
+        'certificate_transparency/mock_log_dns_traffic.cc',
+        'certificate_transparency/mock_log_dns_traffic.h',
+      ],
+    },
   ],
 }