Add a new gyp flag: fieldtrial_testing_like_official_build

build/config/features.gni

 # Copyright 2014 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.
 
 # This file contains Chrome-feature-related build flags (see ui.gni for
 # UI-related ones). These should theoretically be moved to the build files of
 # the features themselves.
 #
 # However, today we have many "bad" dependencies on some of these flags from,
 # e.g. base, so they need to be global to match the GYP configuration. Also,
@@ skipping 87 matching lines @@
   # reporting features for use with Data Saver on Mobile, and 3 enables
   # extended mobile protection via an external API.  When 3 is fully deployed,
   # it will replace 2.
   if (is_android) {
     safe_browsing_mode = 2
   } else if (is_ios) {
     safe_browsing_mode = 0
   } else {
     safe_browsing_mode = 1
   }
+
+  # Set to true make a build that disables activation of field trial tests
+  # specified in testing/variations/fieldtrial_testing_config_*.json.
+  # Note: this setting is ignored if is_chrome_branded.
+  fieldtrial_testing_like_official_build = is_chrome_branded
 }
 
 # Additional dependent variables -----------------------------------------------
 
 # Set the version of CLD.
 #   0: Don't specify the version. This option is for the Finch testing.
 #   1: Use only CLD1.
 #   2: Use only CLD2.
 if (is_android) {
   cld_version = 1
@@ skipping 77 matching lines @@
 # Hangout services is an extension that adds extra features to Hangouts.
 # For official GYP builds, this flag is set, it will likely need to be
 # parameterized in the future for a similar use.
 enable_hangout_services_extension = false
 
 # Whether to back up data before sync.
 enable_pre_sync_backup = is_win || is_mac || (is_linux && !is_chromeos)
 
 # WebVR support disabled until platform implementations have been added
 enable_webvr = false