chrome: remove --disable-async-dns switch

chrome/common/chrome_switches.h

 // 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.
 
 // Defines the shared command-line switches used by code in the Chrome
 // directory that don't have anywhere more specific to go.
 
 #ifndef CHROME_COMMON_CHROME_SWITCHES_H_
 #define CHROME_COMMON_CHROME_SWITCHES_H_
 
@@ skipping 48 matching lines @@
 extern const char kCrashOnHangThreads[];
 extern const char kCreateBrowserOnStartupForTests[];
 extern const char kDebugEnableFrameToggle[];
 extern const char kDebugPackedApps[];
 extern const char kDevToolsFlags[];
 extern const char kDiagnostics[];
 extern const char kDiagnosticsFormat[];
 extern const char kDiagnosticsRecovery[];
 extern const char kDisableAboutInSettings[];
 extern const char kDisableAddToShelf[];
-extern const char kDisableAsyncDns[];
 extern const char kDisableBackgroundNetworking[];
 extern const char kDisableBundledPpapiFlash[];
 extern const char kDisableCastStreamingHWEncoding[];
 extern const char kDisableChildAccountDetection[];
 extern const char kDisableClearBrowsingDataCounters[];
 extern const char kDisableClientSidePhishingDetection[];
 extern const char kDisableComponentExtensionsWithBackgroundPages[];
 extern const char kDisableComponentUpdate[];
 extern const char kDisableDefaultApps[];
 extern const char kDisableDeviceDiscoveryNotifications[];
@@ skipping 325 matching lines @@
 #if defined(OS_CHROMEOS)
 bool PowerOverlayEnabled();
 #endif
 
 // DON'T ADD RANDOM STUFF HERE. Put it in the main section above in
 // alphabetical order, or in one of the ifdefs (also in order in each section).
 
 }  // namespace switches
 
 #endif  // CHROME_COMMON_CHROME_SWITCHES_H_