Remove the #enable-fast-user-switcher flag.

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 <iterator>
 #include <map>
 #include <set>
 #include <utility>
@@ skipping 1537 matching lines @@
   },
   {
     "enable-account-consistency",
     IDS_FLAGS_ENABLE_ACCOUNT_CONSISTENCY_NAME,
     IDS_FLAGS_ENABLE_ACCOUNT_CONSISTENCY_DESCRIPTION,
     kOsAndroid | kOsMac | kOsWin | kOsLinux | kOsCrOS,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableAccountConsistency,
                               switches::kDisableAccountConsistency)
   },
   {
-    "enable-fast-user-switching",
-    IDS_FLAGS_ENABLE_FAST_USER_SWITCHING_NAME,
-    IDS_FLAGS_ENABLE_FAST_USER_SWITCHING_DESCRIPTION,
-    kOsMac | kOsWin | kOsLinux,
-    SINGLE_VALUE_TYPE(switches::kFastUserSwitching)
-  },
-  {
     "enable-new-avatar-menu",
     IDS_FLAGS_ENABLE_NEW_AVATAR_MENU_NAME,
     IDS_FLAGS_ENABLE_NEW_AVATAR_MENU_DESCRIPTION,
     kOsMac | kOsWin | kOsLinux,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableNewAvatarMenu,
                               switches::kDisableNewAvatarMenu)
   },
   {
     "enable-iframe-based-signin",
     IDS_FLAGS_ENABLE_IFRAME_BASED_SIGNIN_NAME,
@@ skipping 1441 matching lines @@
 }
 
 const Experiment* GetExperiments(size_t* count) {
   *count = num_experiments;
   return experiments;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags