Only show the credit card assist feature in secure contexts.

components/autofill/core/browser/autofill_assistant.cc

Index: components/autofill/core/browser/autofill_assistant.cc
diff --git a/components/autofill/core/browser/autofill_assistant.cc b/components/autofill/core/browser/autofill_assistant.cc
index 982dd0591716353cf0a97e28c10aa2e7c2c85d75..f28655a353e8ff3a27214b1f0d4f76d1c68ed27c 100644
--- a/components/autofill/core/browser/autofill_assistant.cc
+++ b/components/autofill/core/browser/autofill_assistant.cc
@@ -32,11 +32,13 @@ bool AutofillAssistant::CanShowCreditCardAssist(
 
   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) {