[net] Add AsyncDns field trial.

chrome/browser/about_flags.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/about_flags.h"
 
 #include <algorithm>
 #include <iterator>
 #include <map>
 #include <set>
@@ skipping 130 matching lines @@
 };
 
 const Experiment::Choice kPointerLockUIChoices[] = {
   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
     switches::kEnablePointerLock, ""},
   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
     switches::kDisablePointerLock, ""}
 };
 
+const Experiment::Choice kAsyncDnsChoices[] = {
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
+    switches::kDisableAsyncDns, ""},
+  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
+    switches::kEnableAsyncDns, ""}
+};
+
 
 // RECORDING USER METRICS FOR FLAGS:
 // -----------------------------------------------------------------------------
 // The first line of the experiment is the internal name. If you'd like to
 // gather statistics about the usage of your flag, you should append a marker
 // comment to the end of the feature name, like so:
 //   "my-special-feature",  // FLAGS:RECORD_UMA
 //
 // After doing that, run //chrome/tools/extract_actions.py (see instructions at
 // the top of that file for details) to update the chromeactions.txt file, which
@@ skipping 354 matching lines @@
     "enable-spdy3",
     IDS_FLAGS_ENABLE_SPDY3_NAME,
     IDS_FLAGS_ENABLE_SPDY3_DESCRIPTION,
     kOsAll,
     SINGLE_VALUE_TYPE(switches::kEnableSpdy3)
   },
   {
     "enable-async-dns",
     IDS_FLAGS_ENABLE_ASYNC_DNS_NAME,
     IDS_FLAGS_ENABLE_ASYNC_DNS_DESCRIPTION,
-    kOsWin | kOsMac | kOsLinux | kOsCrOS,
-    SINGLE_VALUE_TYPE(switches::kEnableAsyncDns)
+    kOsWin | kOsMac | kOsLinux,
+    MULTI_VALUE_TYPE(kAsyncDnsChoices)
   },
   {
     "enable-video-track",
     IDS_FLAGS_ENABLE_VIDEO_TRACK_NAME,
     IDS_FLAGS_ENABLE_VIDEO_TRACK_DESCRIPTION,
     kOsAll,
     SINGLE_VALUE_TYPE(switches::kEnableVideoTrack)
   },
   {
     "enable-media-source",
@@ skipping 813 matching lines @@
 }
 
 const Experiment* GetExperiments(size_t* count) {
   *count = num_experiments;
   return experiments;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags