[Autofill] Implement Autofill Assistant infobar for iOS

components/autofill/core/browser/autofill_assistant.cc

 // Copyright 2016 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/core/browser/autofill_assistant.h"
 
 #include "base/containers/adapters.h"
 #include "base/strings/string16.h"
 #include "components/autofill/core/browser/autofill_experiments.h"
 #include "components/autofill/core/browser/autofill_manager.h"
 #include "components/autofill/core/browser/credit_card.h"
 #include "components/autofill/core/browser/form_structure.h"
 #include "components/autofill/core/common/autofill_constants.h"
 
 namespace autofill {
 
 AutofillAssistant::AutofillAssistant(AutofillManager* autofill_manager)
     : credit_card_form_data_(nullptr),
       autofill_manager_(autofill_manager),
       weak_ptr_factory_(this) {}
 
 AutofillAssistant::~AutofillAssistant() {}
 
 void AutofillAssistant::Reset() {
   credit_card_form_data_.reset();
 }
 
 bool AutofillAssistant::CanShowCreditCardAssist(
     const std::vector<FormStructure*>& form_structures) {
-#if !defined(OS_ANDROID)
-  return false;
-#else
   if (!IsAutofillCreditCardAssistEnabled() || credit_card_form_data_)
     return false;
 
   for (FormStructure* cur_form : base::Reversed(form_structures)) {
     if (cur_form->IsCompleteCreditCardForm()) {
       credit_card_form_data_.reset(new FormData(cur_form->ToFormData()));
       break;
     }
   }
   return !!credit_card_form_data_;
-#endif
 }
 
 void AutofillAssistant::ShowAssistForCreditCard(const CreditCard& card) {
   DCHECK(credit_card_form_data_);
   autofill_manager_->client()->ConfirmCreditCardFillAssist(
       card, base::Bind(&AutofillAssistant::OnUserDidAcceptCreditCardFill,
                        weak_ptr_factory_.GetWeakPtr(), card));
 }
 
 void AutofillAssistant::OnUserDidAcceptCreditCardFill(const CreditCard& card) {
   // TODO(crbug.com/630656): Trigger CVC dialog flow for card filling.
   autofill_manager_->FillCreditCardForm(kNoQueryId, *credit_card_form_data_,
                                         credit_card_form_data_->fields[0], card,
                                         base::string16());
 }
 
 }  // namespace autofill