Enable compilation of //components/autofill on iOS with gn.

components/autofill/ios/browser/autofill_field_trial_ios.cc

-// Copyright 2015 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 "components/autofill/ios/browser/autofill_field_trial_ios.h"
-
-#include "base/command_line.h"
-#include "base/metrics/field_trial.h"
-#include "components/autofill/core/common/autofill_switches.h"
-
-namespace autofill {
-
-// The full-form Autofill field trial name.
-const char kFullFormFieldTrialName[] = "FullFormAutofill";
-
-// static
-bool AutofillFieldTrialIOS::IsFullFormAutofillEnabled() {
-  // Query the field trial state first to ensure that UMA reports the correct
-  // group.
-  std::string field_trial_state =
-      base::FieldTrialList::FindFullName(kFullFormFieldTrialName);
-
-  const base::CommandLine* command_line =
-      base::CommandLine::ForCurrentProcess();
-  if (command_line->HasSwitch(switches::kDisableFullFormAutofillIOS))
-    return false;
-  if (command_line->HasSwitch(switches::kEnableFullFormAutofillIOS))
-    return true;
-
-  return !field_trial_state.empty() && field_trial_state != "Disabled";
-}
-
-}  // namespace autofill