Improve autofill form matching.

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 606 matching lines @@
 
   return has_text_field;
 }
 
 bool FormStructure::ShouldBeCrowdsourced() const {
   return (has_password_field_ ||
           active_field_count() >= kRequiredFieldsForPredictionRoutines) &&
          ShouldBeParsed();
 }
 
-void FormStructure::UpdateFromCache(const FormStructure& cached_form) {
+void FormStructure::UpdateFromCache(const FormStructure& cached_form,
+                                    const bool apply_is_autofilled) {
   // Map from field signatures to cached fields.
-  std::map<std::string, const AutofillField*> cached_fields;
+  std::map<base::string16, const AutofillField*> cached_fields;
   for (size_t i = 0; i < cached_form.field_count(); ++i) {
     auto* const field = cached_form.field(i);
-    cached_fields[field->FieldSignatureAsStr()] = field;
+    cached_fields[field->unique_name()] = field;

[sense (YandexTeam), 2017/03/07 07:10:28]

unique_name() is logically the same as FormSignatureAsStr(), but it doesn't
perform calculation each time it's called.
This variant was used in AutofillManager::UpdateCachedForm().

If there is some hidden quirks that I don't know about, please correct me.

   }
-
   for (auto& field : *this) {
-    std::map<std::string, const AutofillField*>::const_iterator cached_field =
-        cached_fields.find(field->FieldSignatureAsStr());
+    const auto& cached_field = cached_fields.find(field->unique_name());
     if (cached_field != cached_fields.end()) {
       if (field->form_control_type != "select-one" &&
           field->value == cached_field->second->value) {
         // From the perspective of learning user data, text fields containing
         // default values are equivalent to empty fields.
         field->value = base::string16();
       }
 
       // Transfer attributes of the cached AutofillField to the newly created
       // AutofillField.
       field->set_heuristic_type(cached_field->second->heuristic_type());
       field->set_server_type(cached_field->second->server_type());
       field->SetHtmlType(cached_field->second->html_type(),
                          cached_field->second->html_mode());
+      if (apply_is_autofilled) {
+        field->is_autofilled = cached_field->second->is_autofilled;
+      }
       field->set_previously_autofilled(
           cached_field->second->previously_autofilled());
       field->set_section(cached_field->second->section());
     }
   }
 
   UpdateAutofillCount();
 
   // The form signature should match between query and upload requests to the
   // server. On many websites, form elements are dynamically added, removed, or
   // rearranged via JavaScript between page load and form submission, so we
   // copy over the |form_signature_field_names_| corresponding to the query
   // request.
-  DCHECK_EQ(cached_form.form_name_, form_name_);

[sense (YandexTeam), 2017/03/07 07:10:28]

These DCHECKs were removed because the form now can be matched using
form_signature.

-  DCHECK_EQ(cached_form.source_url_, source_url_);
-  DCHECK_EQ(cached_form.target_url_, target_url_);
   form_signature_ = cached_form.form_signature_;
 }
 
 void FormStructure::LogQualityMetrics(const base::TimeTicks& load_time,
                                       const base::TimeTicks& interaction_time,
                                       const base::TimeTicks& submission_time,
                                       rappor::RapporServiceImpl* rappor_service,
                                       bool did_show_suggestions,
                                       bool observed_submission) const {
   size_t num_detected_field_types = 0;
@@ skipping 642 matching lines @@
               filtered_strings[0].at(prefix_len)) {
         // Mismatch found.
         return filtered_strings[i].substr(0, prefix_len);
       }
     }
   }
   return filtered_strings[0];
 }
 
 }  // namespace autofill