[net] Add AsyncDns field trial.

chrome/common/chrome_switches.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/common/chrome_switches.h"
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
 
 namespace switches {
@@ skipping 232 matching lines @@
 // device management backend.
 const char kDeviceManagementUrl[]           = "device-management-url";
 
 // Triggers a plethora of diagnostic modes.
 const char kDiagnostics[]                   = "diagnostics";
 
 // Replaces the audio IPC layer for <audio> and <video> with a mock audio
 // device, useful when using remote desktop or machines without sound cards.
 // This is temporary until we fix the underlying problem.
 
+// Disables the experimental asynchronous DNS client.
+const char kDisableAsyncDns[]               = "disable-async-dns";
+
 // Disables asynchronous spellchecking features for all time. Disabling this
 // feature also disables unified spellchecking.
 const char kDisableAsynchronousSpellChecking[] =
     "disable-asynchronous-spellchecking";
 
 // Disables CNAME lookup of the host when generating the Kerberos SPN for a
 // Negotiate challenge. See HttpAuthHandlerNegotiate::CreateSPN for more
 // background.
 const char kDisableAuthNegotiateCnameLookup[] =
     "disable-auth-negotiate-cname-lookup";
@@ skipping 1351 matching lines @@
 
 // -----------------------------------------------------------------------------
 // DO NOT ADD YOUR CRAP TO THE BOTTOM OF THIS FILE.
 //
 // You were going to just dump your switches here, weren't you? Instead, please
 // put them in alphabetical order above, or in order inside the appropriate
 // ifdef at the bottom. The order should match the header.
 // -----------------------------------------------------------------------------
 
 }  // namespace switches