Sending autofill types for username fields in sign-in forms for improving username detection.

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 1989 matching lines @@
 // static
 void AutofillManager::DeterminePossibleFieldTypesForUpload(
     const std::vector<AutofillProfile>& profiles,
     const std::vector<CreditCard>& credit_cards,
     const std::string& app_locale,
     FormStructure* submitted_form) {
   // For each field in the |submitted_form|, extract the value.  Then for each
   // profile or credit card, identify any stored types that match the value.
   for (size_t i = 0; i < submitted_form->field_count(); ++i) {
     AutofillField* field = submitted_form->field(i);
-    ServerFieldTypeSet matching_types;
+    ServerFieldTypeSet matching_types = field->possible_types();

[Roger McFarlane (Chromium), 2017/04/07 03:20:59]

Is there a way to refactor this such that we don't expect the field to magically
have possible_types before having been passed to this method. It bakes in the
assumption that the password manager previously populated this field.

I'd rather see something like

  field.reset_possible_types();
  for (const auto& profile : profiles)
    field.add_possible_types(profile.GetMatchingTypes(value, app_locale));
  for (const auto& card : credit_cards)
    field.add_possible_types(card.GetMatchingTypes(value, app_locale));
  for (const auto& login : logins)
    field.add_possible_type(login.GetMatchingTypes(value, app_locale));

[dvadym, 2017/04/07 09:09:01]

Yeah, it would look better here, but it looks like such structure isn't suitable
for login information: all other autofill types are user personal information
and they are stored in the user profile, on other hand passwords are unique and
they are determined during saving, so we can't match value against profile.
Moreover Password Manager will set only one type - PASSWORD, basically we need
this type here only for finding password forms/fields server-side.

 
     base::string16 value;
     base::TrimWhitespace(field->value, base::TRIM_ALL, &value);
 
     for (const AutofillProfile& profile : profiles)
       profile.GetMatchingTypes(value, app_locale, &matching_types);
     for (const CreditCard& card : credit_cards)
       card.GetMatchingTypes(value, app_locale, &matching_types);
 
     if (matching_types.empty())
@@ skipping 177 matching lines @@
 }
 #endif  // ENABLE_FORM_DEBUG_DUMP
 
 void AutofillManager::LogCardUploadDecisionUkm(
     AutofillMetrics::CardUploadDecisionMetric upload_decision) {
   AutofillMetrics::LogCardUploadDecisionUkm(
       client_->GetUkmService(), pending_upload_request_url_, upload_decision);
 }
 
 }  // namespace autofill