[Autofill] Remove warning for CC autofill on secure pages with mixed passive content

components/autofill/core/browser/autofill_manager.cc

 // Copyright 2013 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_manager.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 423 matching lines @@
         !field.should_autocomplete) {
       return;
     }
     if (is_filling_credit_card) {
       suggestions = GetCreditCardSuggestions(field, type);
     } else {
       suggestions =
           GetProfileSuggestions(*form_structure, field, *autofill_field);
     }
     if (!suggestions.empty()) {
-      // Don't provide credit card suggestions for non-secure pages. However,
-      // do provide a warning to the user. This will generate warnings on pages
-      // with mixed content (which includes forms with an http target).
+      // Don't provide credit card suggestions for non-secure pages, but do
+      // provide them for secure pages with passive mixed content (see impl. of
+      // IsContextSecure).
       if (is_filling_credit_card &&
           !client_->IsContextSecure(form_structure->source_url())) {
         Suggestion warning_suggestion(l10n_util::GetStringUTF16(
             IDS_AUTOFILL_WARNING_INSECURE_CONNECTION));
         warning_suggestion.frontend_id = POPUP_ITEM_ID_WARNING_MESSAGE;
         suggestions.assign(1, warning_suggestion);
       } else {
         bool section_is_autofilled =
             SectionIsAutofilled(*form_structure, form,
                                 autofill_field->section());
@@ skipping 1270 matching lines @@
     if (i > 0)
       fputs("Next oldest form:\n", file);
   }
   fputs("\n", file);
 
   fclose(file);
 }
 #endif  // ENABLE_FORM_DEBUG_DUMP
 
 }  // namespace autofill