Only show the credit card assist feature in secure contexts.

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"
@@ skipping 14 matching lines @@
   credit_card_form_data_.reset();
 }
 
 bool AutofillAssistant::CanShowCreditCardAssist(
     const std::vector<FormStructure*>& form_structures) {
   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()));
+      const FormData& cur_form_data = cur_form->ToFormData();

[sebsg, 2016/08/19 14:23:01]

Since forms sometimes have a lot of fields, I think it would be more efficient
to check for the secure context first?

Looks like checking the context is O(1) and checking if it's a complete credit
card form is O(n) where n is the number of fields in the form.

It should be negligible in practice though so it's up to you.

[Roger McFarlane (Chromium), 2016/08/19 15:23:41]

Done.

+      if (autofill_manager_->client()->IsContextSecure(cur_form_data.origin))
+        credit_card_form_data_.reset(new FormData(cur_form_data));
       break;
     }
   }
-  return !!credit_card_form_data_;
+  return credit_card_form_data_ != nullptr;
 }
 
 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