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

components/autofill/core/browser/form_structure.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/form_structure.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 #include <map>
@@ skipping 291 matching lines @@
       autofill_count_(0),
       active_field_count_(0),
       upload_required_(USE_UPLOAD_RATES),
       has_author_specified_types_(false),
       has_author_specified_sections_(false),
       has_author_specified_upi_vpa_hint_(false),
       was_parsed_for_autocomplete_attributes_(false),
       has_password_field_(false),
       is_form_tag_(form.is_form_tag),
       is_formless_checkout_(form.is_formless_checkout),
-      all_fields_are_passwords_(true) {
+      all_fields_are_passwords_(true),
+      is_signin_upload_(false) {
   // Copy the form fields.
   std::map<base::string16, size_t> unique_names;
   for (const FormFieldData& field : form.fields) {
     if (!ShouldSkipField(field))
       ++active_field_count_;
 
     if (field.form_control_type == "password")
       has_password_field_ = true;
     else
       all_fields_are_passwords_ = false;
@@ skipping 283 matching lines @@
   for (const auto& field : *this) {
     if (field && field->IsFieldFillable())
       ++autofill_count_;
   }
 }
 
 bool FormStructure::ShouldBeParsed() const {
   if (active_field_count() < kRequiredFieldsForPredictionRoutines &&
       (!all_fields_are_passwords() ||
        active_field_count() < kRequiredFieldsForFormsWithOnlyPasswordFields) &&
-      !has_author_specified_types_) {
+      !is_signin_upload_ && !has_author_specified_types_) {

[Roger McFarlane (Chromium), 2017/04/04 19:09:42]

hmm... digging into this boolean logic...

The change here is to allow signing upload forms to be parsed, even though they
don't fit the other # of fields minimums, right?

I read this as "Do not parse the form if...

  there are too few fields in general
    AND (some fields are not passwords
         OR (there are too few fields for passwords only
             AND its not a signin upload
             AND there are no author specified types
            )
        )"

Plz confirm that this is what you intended?

[dvadym, 2017/04/05 13:28:28]

Yes, it's correct, it allows sign-in uploads to be parsed, and only uploads, not
queries for such forms. 

     return false;
   }
 
   // Rule out http(s)://*/search?...
   //  e.g. http://www.google.com/search?q=...
   //       http://search.yahoo.com/search?p=...
   if (target_url_.path_piece() == "/search")
     return false;
 
   bool has_text_field = false;
@@ skipping 711 matching lines @@
               filtered_strings[0].at(prefix_len)) {
         // Mismatch found.
         return filtered_strings[i].substr(0, prefix_len);
       }
     }
   }
   return filtered_strings[0];
 }
 
 }  // namespace autofill