[Autofill] Fill fields that have an autocomplete attributes even if not in a form.

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 286 matching lines @@
     : form_name_(form.name),
       source_url_(form.origin),
       target_url_(form.action),
       autofill_count_(0),
       active_field_count_(0),
       upload_required_(USE_UPLOAD_RATES),
       has_author_specified_types_(false),
       has_author_specified_sections_(false),
       was_parsed_for_autocomplete_attributes_(false),
       has_password_field_(false),
-      is_form_tag_(form.is_form_tag) {
+      is_form_tag_(form.is_form_tag),
+      is_formless_checkout_(form.is_formless_checkout) {
   // Copy the form fields.
   std::map<base::string16, size_t> unique_names;
   for (const FormFieldData& field : form.fields) {
     if (!ShouldSkipField(field)) {
       // Add all supported form fields (including with empty names) to the
       // signature.  This is a requirement for Autofill servers.
       form_signature_field_names_.append("&");
       form_signature_field_names_.append(StripDigitsIfRequired(field.name));
 
       ++active_field_count_;
@@ skipping 12 matching lines @@
   }
 
   // Do further processing on the fields, as needed.
   ProcessExtractedFields();
 }
 
 FormStructure::~FormStructure() {}
 
 void FormStructure::DetermineHeuristicTypes() {
   // First, try to detect field types based on each field's |autocomplete|
-  // attribute value.  If there is at least one form field that specifies an
-  // autocomplete type hint, don't try to apply other heuristics to match fields
-  // in this form.
+  // attribute value.
   if (!was_parsed_for_autocomplete_attributes_)
     ParseFieldTypesFromAutocompleteAttributes();
 
-  if (active_field_count() >= kRequiredFieldsForPredictionRoutines) {
+  // Then if there are enough active fields, and if we are dealing with either a
+  // proper <form> or a <form>-less checkout, run the heuristics and server
+  // prediction routines.
+  if (active_field_count() >= kRequiredFieldsForPredictionRoutines &&
+      (is_form_tag_ || is_formless_checkout_)) {
     ServerFieldTypeMap field_type_map;
     FormField::ParseFormFields(fields_.get(), is_form_tag_, &field_type_map);
     for (size_t i = 0; i < field_count(); ++i) {
       AutofillField* field = fields_[i];
       ServerFieldTypeMap::iterator iter =
           field_type_map.find(field->unique_name());
       if (iter != field_type_map.end())
         field->set_heuristic_type(iter->second);
     }
   }
@@ skipping 933 matching lines @@
           strings[i].at(prefix_len) != strings[0].at(prefix_len)) {
         // Mismatch found.
         return base::StringPiece16(strings[i].data(), prefix_len);
       }
     }
   }
   return strings[0];
 }
 
 }  // namespace autofill