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      1 // Copyright 2013 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "components/autofill/core/browser/form_structure.h"
      6 
      7 #include <utility>
      8 
      9 #include "base/basictypes.h"
     10 #include "base/command_line.h"
     11 #include "base/logging.h"
     12 #include "base/memory/scoped_ptr.h"
     13 #include "base/sha1.h"
     14 #include "base/strings/string_number_conversions.h"
     15 #include "base/strings/string_util.h"
     16 #include "base/strings/stringprintf.h"
     17 #include "base/strings/utf_string_conversions.h"
     18 #include "base/time/time.h"
     19 #include "components/autofill/core/browser/autofill_metrics.h"
     20 #include "components/autofill/core/browser/autofill_type.h"
     21 #include "components/autofill/core/browser/autofill_xml_parser.h"
     22 #include "components/autofill/core/browser/field_types.h"
     23 #include "components/autofill/core/browser/form_field.h"
     24 #include "components/autofill/core/common/autofill_constants.h"
     25 #include "components/autofill/core/common/form_data.h"
     26 #include "components/autofill/core/common/form_data_predictions.h"
     27 #include "components/autofill/core/common/form_field_data.h"
     28 #include "components/autofill/core/common/form_field_data_predictions.h"
     29 #include "third_party/icu/source/i18n/unicode/regex.h"
     30 #include "third_party/libjingle/source/talk/xmllite/xmlelement.h"
     31 
     32 namespace autofill {
     33 namespace {
     34 
     35 const char kFormMethodPost[] = "post";
     36 
     37 // XML elements and attributes.
     38 const char kAttributeAcceptedFeatures[] = "accepts";
     39 const char kAttributeAutofillUsed[] = "autofillused";
     40 const char kAttributeAutofillType[] = "autofilltype";
     41 const char kAttributeClientVersion[] = "clientversion";
     42 const char kAttributeDataPresent[] = "datapresent";
     43 const char kAttributeFieldID[] = "fieldid";
     44 const char kAttributeFieldType[] = "fieldtype";
     45 const char kAttributeFormSignature[] = "formsignature";
     46 const char kAttributeName[] = "name";
     47 const char kAttributeSignature[] = "signature";
     48 const char kAcceptedFeaturesExperiment[] = "e"; // e=experiments
     49 const char kClientVersion[] = "6.1.1715.1442/en (GGLL)";
     50 const char kXMLDeclaration[] = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>";
     51 const char kXMLElementAutofillQuery[] = "autofillquery";
     52 const char kXMLElementAutofillUpload[] = "autofillupload";
     53 const char kXMLElementFieldAssignments[] = "fieldassignments";
     54 const char kXMLElementField[] = "field";
     55 const char kXMLElementFields[] = "fields";
     56 const char kXMLElementForm[] = "form";
     57 const char kBillingMode[] = "billing";
     58 const char kShippingMode[] = "shipping";
     59 
     60 // Stip away >= 5 consecutive digits.
     61 const char kIgnorePatternInFieldName[] = "\\d{5,}+";
     62 
     63 // Helper for |EncodeUploadRequest()| that creates a bit field corresponding to
     64 // |available_field_types| and returns the hex representation as a string.
     65 std::string EncodeFieldTypes(const ServerFieldTypeSet& available_field_types) {
     66   // There are |MAX_VALID_FIELD_TYPE| different field types and 8 bits per byte,
     67   // so we need ceil(MAX_VALID_FIELD_TYPE / 8) bytes to encode the bit field.
     68   const size_t kNumBytes = (MAX_VALID_FIELD_TYPE + 0x7) / 8;
     69 
     70   // Pack the types in |available_field_types| into |bit_field|.
     71   std::vector<uint8> bit_field(kNumBytes, 0);
     72   for (ServerFieldTypeSet::const_iterator field_type =
     73            available_field_types.begin();
     74        field_type != available_field_types.end();
     75        ++field_type) {
     76     // Set the appropriate bit in the field.  The bit we set is the one
     77     // |field_type| % 8 from the left of the byte.
     78     const size_t byte = *field_type / 8;
     79     const size_t bit = 0x80 >> (*field_type % 8);
     80     DCHECK(byte < bit_field.size());
     81     bit_field[byte] |= bit;
     82   }
     83 
     84   // Discard any trailing zeroes.
     85   // If there are no available types, we return the empty string.
     86   size_t data_end = bit_field.size();
     87   for (; data_end > 0 && !bit_field[data_end - 1]; --data_end) {
     88   }
     89 
     90   // Print all meaningfull bytes into a string.
     91   std::string data_presence;
     92   data_presence.reserve(data_end * 2 + 1);
     93   for (size_t i = 0; i < data_end; ++i) {
     94     base::StringAppendF(&data_presence, "%02x", bit_field[i]);
     95   }
     96 
     97   return data_presence;
     98 }
     99 
    100 // Helper for |EncodeFormRequest()| that creates XmlElements for the given field
    101 // in upload xml, and also add them to the parent XmlElement.
    102 void EncodeFieldForUpload(const AutofillField& field,
    103                           buzz::XmlElement* parent) {
    104   // Don't upload checkable fields.
    105   if (field.is_checkable)
    106     return;
    107 
    108   ServerFieldTypeSet types = field.possible_types();
    109   // |types| could be empty in unit-tests only.
    110   for (ServerFieldTypeSet::iterator field_type = types.begin();
    111        field_type != types.end(); ++field_type) {
    112     buzz::XmlElement *field_element = new buzz::XmlElement(
    113         buzz::QName(kXMLElementField));
    114 
    115     field_element->SetAttr(buzz::QName(kAttributeSignature),
    116                            field.FieldSignature());
    117     field_element->SetAttr(buzz::QName(kAttributeAutofillType),
    118                            base::IntToString(*field_type));
    119     parent->AddElement(field_element);
    120   }
    121 }
    122 
    123 // Helper for |EncodeFormRequest()| that creates XmlElement for the given field
    124 // in query xml, and also add it to the parent XmlElement.
    125 void EncodeFieldForQuery(const AutofillField& field,
    126                          buzz::XmlElement* parent) {
    127   buzz::XmlElement *field_element = new buzz::XmlElement(
    128       buzz::QName(kXMLElementField));
    129   field_element->SetAttr(buzz::QName(kAttributeSignature),
    130                          field.FieldSignature());
    131   parent->AddElement(field_element);
    132 }
    133 
    134 // Helper for |EncodeFormRequest()| that creates XmlElements for the given field
    135 // in field assignments xml, and also add them to the parent XmlElement.
    136 void EncodeFieldForFieldAssignments(const AutofillField& field,
    137                                     buzz::XmlElement* parent) {
    138   ServerFieldTypeSet types = field.possible_types();
    139   for (ServerFieldTypeSet::iterator field_type = types.begin();
    140        field_type != types.end(); ++field_type) {
    141     buzz::XmlElement *field_element = new buzz::XmlElement(
    142         buzz::QName(kXMLElementFields));
    143 
    144     field_element->SetAttr(buzz::QName(kAttributeFieldID),
    145                            field.FieldSignature());
    146     field_element->SetAttr(buzz::QName(kAttributeFieldType),
    147                            base::IntToString(*field_type));
    148     field_element->SetAttr(buzz::QName(kAttributeName),
    149                            UTF16ToUTF8(field.name));
    150     parent->AddElement(field_element);
    151   }
    152 }
    153 
    154 // Returns |true| iff the |token| is a type hint for a contact field, as
    155 // specified in the implementation section of http://is.gd/whatwg_autocomplete
    156 // Note that "fax" and "pager" are intentionally ignored, as Chrome does not
    157 // support filling either type of information.
    158 bool IsContactTypeHint(const std::string& token) {
    159   return token == "home" || token == "work" || token == "mobile";
    160 }
    161 
    162 // Returns |true| iff the |token| is a type hint appropriate for a field of the
    163 // given |field_type|, as specified in the implementation section of
    164 // http://is.gd/whatwg_autocomplete
    165 bool ContactTypeHintMatchesFieldType(const std::string& token,
    166                                      HtmlFieldType field_type) {
    167   // The "home" and "work" type hints are only appropriate for email and phone
    168   // number field types.
    169   if (token == "home" || token == "work") {
    170     return field_type == HTML_TYPE_EMAIL ||
    171         (field_type >= HTML_TYPE_TEL &&
    172          field_type <= HTML_TYPE_TEL_LOCAL_SUFFIX);
    173   }
    174 
    175   // The "mobile" type hint is only appropriate for phone number field types.
    176   // Note that "fax" and "pager" are intentionally ignored, as Chrome does not
    177   // support filling either type of information.
    178   if (token == "mobile") {
    179     return field_type >= HTML_TYPE_TEL &&
    180         field_type <= HTML_TYPE_TEL_LOCAL_SUFFIX;
    181   }
    182 
    183   return false;
    184 }
    185 
    186 // Returns the Chrome Autofill-supported field type corresponding to the given
    187 // |autocomplete_attribute_value|, if there is one, in the context of the given
    188 // |field|.  Chrome Autofill supports a subset of the field types listed at
    189 // http://is.gd/whatwg_autocomplete
    190 HtmlFieldType FieldTypeFromAutocompleteAttributeValue(
    191     const std::string& autocomplete_attribute_value,
    192     const AutofillField& field) {
    193   if (autocomplete_attribute_value == "name")
    194     return HTML_TYPE_NAME;
    195 
    196   if (autocomplete_attribute_value == "given-name")
    197     return HTML_TYPE_GIVEN_NAME;
    198 
    199   if (autocomplete_attribute_value == "additional-name") {
    200     if (field.max_length == 1)
    201       return HTML_TYPE_ADDITIONAL_NAME_INITIAL;
    202     else
    203       return HTML_TYPE_ADDITIONAL_NAME;
    204   }
    205 
    206   if (autocomplete_attribute_value == "family-name")
    207     return HTML_TYPE_FAMILY_NAME;
    208 
    209   if (autocomplete_attribute_value == "organization")
    210     return HTML_TYPE_ORGANIZATION;
    211 
    212   if (autocomplete_attribute_value == "street-address")
    213     return HTML_TYPE_STREET_ADDRESS;
    214 
    215   if (autocomplete_attribute_value == "address-line1")
    216     return HTML_TYPE_ADDRESS_LINE1;
    217 
    218   if (autocomplete_attribute_value == "address-line2")
    219     return HTML_TYPE_ADDRESS_LINE2;
    220 
    221   if (autocomplete_attribute_value == "locality")
    222     return HTML_TYPE_LOCALITY;
    223 
    224   if (autocomplete_attribute_value == "region")
    225     return HTML_TYPE_REGION;
    226 
    227   if (autocomplete_attribute_value == "country")
    228     return HTML_TYPE_COUNTRY_CODE;
    229 
    230   if (autocomplete_attribute_value == "country-name")
    231     return HTML_TYPE_COUNTRY_NAME;
    232 
    233   if (autocomplete_attribute_value == "postal-code")
    234     return HTML_TYPE_POSTAL_CODE;
    235 
    236   if (autocomplete_attribute_value == "cc-name")
    237     return HTML_TYPE_CREDIT_CARD_NAME;
    238 
    239   if (autocomplete_attribute_value == "cc-number")
    240     return HTML_TYPE_CREDIT_CARD_NUMBER;
    241 
    242   if (autocomplete_attribute_value == "cc-exp") {
    243     if (field.max_length == 5)
    244       return HTML_TYPE_CREDIT_CARD_EXP_DATE_2_DIGIT_YEAR;
    245     else if (field.max_length == 7)
    246       return HTML_TYPE_CREDIT_CARD_EXP_DATE_4_DIGIT_YEAR;
    247     else
    248       return HTML_TYPE_CREDIT_CARD_EXP;
    249   }
    250 
    251   if (autocomplete_attribute_value == "cc-exp-month")
    252     return HTML_TYPE_CREDIT_CARD_EXP_MONTH;
    253 
    254   if (autocomplete_attribute_value == "cc-exp-year") {
    255     if (field.max_length == 2)
    256       return HTML_TYPE_CREDIT_CARD_EXP_2_DIGIT_YEAR;
    257     else if (field.max_length == 4)
    258       return HTML_TYPE_CREDIT_CARD_EXP_4_DIGIT_YEAR;
    259     else
    260       return HTML_TYPE_CREDIT_CARD_EXP_YEAR;
    261   }
    262 
    263   if (autocomplete_attribute_value == "cc-csc")
    264     return HTML_TYPE_CREDIT_CARD_VERIFICATION_CODE;
    265 
    266   if (autocomplete_attribute_value == "cc-type")
    267     return HTML_TYPE_CREDIT_CARD_TYPE;
    268 
    269   if (autocomplete_attribute_value == "tel")
    270     return HTML_TYPE_TEL;
    271 
    272   if (autocomplete_attribute_value == "tel-country-code")
    273     return HTML_TYPE_TEL_COUNTRY_CODE;
    274 
    275   if (autocomplete_attribute_value == "tel-national")
    276     return HTML_TYPE_TEL_NATIONAL;
    277 
    278   if (autocomplete_attribute_value == "tel-area-code")
    279     return HTML_TYPE_TEL_AREA_CODE;
    280 
    281   if (autocomplete_attribute_value == "tel-local")
    282     return HTML_TYPE_TEL_LOCAL;
    283 
    284   if (autocomplete_attribute_value == "tel-local-prefix")
    285     return HTML_TYPE_TEL_LOCAL_PREFIX;
    286 
    287   if (autocomplete_attribute_value == "tel-local-suffix")
    288     return HTML_TYPE_TEL_LOCAL_SUFFIX;
    289 
    290   if (autocomplete_attribute_value == "email")
    291     return HTML_TYPE_EMAIL;
    292 
    293   return HTML_TYPE_UNKNOWN;
    294 }
    295 
    296 std::string StripDigitsIfRequired(const base::string16& input) {
    297   UErrorCode status = U_ZERO_ERROR;
    298   CR_DEFINE_STATIC_LOCAL(icu::UnicodeString, icu_pattern,
    299                          (kIgnorePatternInFieldName));
    300   CR_DEFINE_STATIC_LOCAL(icu::RegexMatcher, matcher,
    301                          (icu_pattern, UREGEX_CASE_INSENSITIVE, status));
    302   DCHECK_EQ(status, U_ZERO_ERROR);
    303 
    304   icu::UnicodeString icu_input(input.data(), input.length());
    305   matcher.reset(icu_input);
    306 
    307   icu::UnicodeString replaced_string = matcher.replaceAll("", status);
    308 
    309   std::string return_string;
    310   status = U_ZERO_ERROR;
    311   UTF16ToUTF8(replaced_string.getBuffer(),
    312               static_cast<size_t>(replaced_string.length()),
    313               &return_string);
    314   if (status != U_ZERO_ERROR) {
    315     DVLOG(1) << "Couldn't strip digits in " << UTF16ToUTF8(input);
    316     return UTF16ToUTF8(input);
    317   }
    318 
    319   return return_string;
    320 }
    321 
    322 }  // namespace
    323 
    324 FormStructure::FormStructure(const FormData& form)
    325     : form_name_(form.name),
    326       source_url_(form.origin),
    327       target_url_(form.action),
    328       autofill_count_(0),
    329       active_field_count_(0),
    330       upload_required_(USE_UPLOAD_RATES),
    331       server_experiment_id_("no server response"),
    332       has_author_specified_types_(false) {
    333   // Copy the form fields.
    334   std::map<base::string16, size_t> unique_names;
    335   for (std::vector<FormFieldData>::const_iterator field =
    336            form.fields.begin();
    337        field != form.fields.end(); ++field) {
    338     if (!ShouldSkipField(*field)) {
    339       // Add all supported form fields (including with empty names) to the
    340       // signature.  This is a requirement for Autofill servers.
    341       form_signature_field_names_.append("&");
    342       form_signature_field_names_.append(StripDigitsIfRequired(field->name));
    343 
    344       ++active_field_count_;
    345     }
    346 
    347     // Generate a unique name for this field by appending a counter to the name.
    348     // Make sure to prepend the counter with a non-numeric digit so that we are
    349     // guaranteed to avoid collisions.
    350     if (!unique_names.count(field->name))
    351       unique_names[field->name] = 1;
    352     else
    353       ++unique_names[field->name];
    354     base::string16 unique_name = field->name + ASCIIToUTF16("_") +
    355         base::IntToString16(unique_names[field->name]);
    356     fields_.push_back(new AutofillField(*field, unique_name));
    357   }
    358 
    359   std::string method = UTF16ToUTF8(form.method);
    360   if (StringToLowerASCII(method) == kFormMethodPost) {
    361     method_ = POST;
    362   } else {
    363     // Either the method is 'get', or we don't know.  In this case we default
    364     // to GET.
    365     method_ = GET;
    366   }
    367 }
    368 
    369 FormStructure::~FormStructure() {}
    370 
    371 void FormStructure::DetermineHeuristicTypes(
    372     const AutofillMetrics& metric_logger) {
    373   // First, try to detect field types based on each field's |autocomplete|
    374   // attribute value.  If there is at least one form field that specifies an
    375   // autocomplete type hint, don't try to apply other heuristics to match fields
    376   // in this form.
    377   bool has_author_specified_sections;
    378   ParseFieldTypesFromAutocompleteAttributes(&has_author_specified_types_,
    379                                             &has_author_specified_sections);
    380 
    381   if (!has_author_specified_types_) {
    382     ServerFieldTypeMap field_type_map;
    383     FormField::ParseFormFields(fields_.get(), &field_type_map);
    384     for (size_t i = 0; i < field_count(); ++i) {
    385       AutofillField* field = fields_[i];
    386       ServerFieldTypeMap::iterator iter =
    387           field_type_map.find(field->unique_name());
    388       if (iter != field_type_map.end())
    389         field->set_heuristic_type(iter->second);
    390     }
    391   }
    392 
    393   UpdateAutofillCount();
    394   IdentifySections(has_author_specified_sections);
    395 
    396   if (IsAutofillable(true)) {
    397     metric_logger.LogDeveloperEngagementMetric(
    398         AutofillMetrics::FILLABLE_FORM_PARSED);
    399     if (has_author_specified_types_) {
    400       metric_logger.LogDeveloperEngagementMetric(
    401           AutofillMetrics::FILLABLE_FORM_CONTAINS_TYPE_HINTS);
    402     }
    403   }
    404 }
    405 
    406 bool FormStructure::EncodeUploadRequest(
    407     const ServerFieldTypeSet& available_field_types,
    408     bool form_was_autofilled,
    409     std::string* encoded_xml) const {
    410   DCHECK(ShouldBeCrowdsourced());
    411 
    412   // Verify that |available_field_types| agrees with the possible field types we
    413   // are uploading.
    414   for (std::vector<AutofillField*>::const_iterator field = begin();
    415        field != end();
    416        ++field) {
    417     for (ServerFieldTypeSet::const_iterator type =
    418              (*field)->possible_types().begin();
    419          type != (*field)->possible_types().end();
    420          ++type) {
    421       DCHECK(*type == UNKNOWN_TYPE ||
    422              *type == EMPTY_TYPE ||
    423              available_field_types.count(*type));
    424     }
    425   }
    426 
    427   // Set up the <autofillupload> element and its attributes.
    428   buzz::XmlElement autofill_request_xml(
    429       (buzz::QName(kXMLElementAutofillUpload)));
    430   autofill_request_xml.SetAttr(buzz::QName(kAttributeClientVersion),
    431                                kClientVersion);
    432   autofill_request_xml.SetAttr(buzz::QName(kAttributeFormSignature),
    433                                FormSignature());
    434   autofill_request_xml.SetAttr(buzz::QName(kAttributeAutofillUsed),
    435                                form_was_autofilled ? "true" : "false");
    436   autofill_request_xml.SetAttr(buzz::QName(kAttributeDataPresent),
    437                                EncodeFieldTypes(available_field_types).c_str());
    438 
    439   if (!EncodeFormRequest(FormStructure::UPLOAD, &autofill_request_xml))
    440     return false;  // Malformed form, skip it.
    441 
    442   // Obtain the XML structure as a string.
    443   *encoded_xml = kXMLDeclaration;
    444   *encoded_xml += autofill_request_xml.Str().c_str();
    445 
    446   // To enable this logging, run with the flag --vmodule="form_structure=2".
    447   VLOG(2) << "\n" << *encoded_xml;
    448 
    449   return true;
    450 }
    451 
    452 bool FormStructure::EncodeFieldAssignments(
    453     const ServerFieldTypeSet& available_field_types,
    454     std::string* encoded_xml) const {
    455   DCHECK(ShouldBeCrowdsourced());
    456 
    457   // Set up the <fieldassignments> element and its attributes.
    458   buzz::XmlElement autofill_request_xml(
    459       (buzz::QName(kXMLElementFieldAssignments)));
    460   autofill_request_xml.SetAttr(buzz::QName(kAttributeFormSignature),
    461                                FormSignature());
    462 
    463   if (!EncodeFormRequest(FormStructure::FIELD_ASSIGNMENTS,
    464                          &autofill_request_xml))
    465     return false;  // Malformed form, skip it.
    466 
    467   // Obtain the XML structure as a string.
    468   *encoded_xml = kXMLDeclaration;
    469   *encoded_xml += autofill_request_xml.Str().c_str();
    470 
    471   return true;
    472 }
    473 
    474 // static
    475 bool FormStructure::EncodeQueryRequest(
    476     const std::vector<FormStructure*>& forms,
    477     std::vector<std::string>* encoded_signatures,
    478     std::string* encoded_xml) {
    479   DCHECK(encoded_signatures);
    480   DCHECK(encoded_xml);
    481   encoded_xml->clear();
    482   encoded_signatures->clear();
    483   encoded_signatures->reserve(forms.size());
    484 
    485   // Set up the <autofillquery> element and attributes.
    486   buzz::XmlElement autofill_request_xml(
    487       (buzz::QName(kXMLElementAutofillQuery)));
    488   autofill_request_xml.SetAttr(buzz::QName(kAttributeClientVersion),
    489                                kClientVersion);
    490 
    491   // Some badly formatted web sites repeat forms - detect that and encode only
    492   // one form as returned data would be the same for all the repeated forms.
    493   std::set<std::string> processed_forms;
    494   for (ScopedVector<FormStructure>::const_iterator it = forms.begin();
    495        it != forms.end();
    496        ++it) {
    497     std::string signature((*it)->FormSignature());
    498     if (processed_forms.find(signature) != processed_forms.end())
    499       continue;
    500     processed_forms.insert(signature);
    501     scoped_ptr<buzz::XmlElement> encompassing_xml_element(
    502         new buzz::XmlElement(buzz::QName(kXMLElementForm)));
    503     encompassing_xml_element->SetAttr(buzz::QName(kAttributeSignature),
    504                                       signature);
    505 
    506     if (!(*it)->EncodeFormRequest(FormStructure::QUERY,
    507                                   encompassing_xml_element.get()))
    508       continue;  // Malformed form, skip it.
    509 
    510     autofill_request_xml.AddElement(encompassing_xml_element.release());
    511     encoded_signatures->push_back(signature);
    512   }
    513 
    514   if (!encoded_signatures->size())
    515     return false;
    516 
    517   autofill_request_xml.SetAttr(buzz::QName(kAttributeAcceptedFeatures),
    518                                kAcceptedFeaturesExperiment);
    519 
    520   // Obtain the XML structure as a string.
    521   *encoded_xml = kXMLDeclaration;
    522   *encoded_xml += autofill_request_xml.Str().c_str();
    523 
    524   return true;
    525 }
    526 
    527 // static
    528 void FormStructure::ParseQueryResponse(
    529     const std::string& response_xml,
    530     const std::vector<FormStructure*>& forms,
    531     const AutofillMetrics& metric_logger) {
    532   metric_logger.LogServerQueryMetric(AutofillMetrics::QUERY_RESPONSE_RECEIVED);
    533 
    534   // Parse the field types from the server response to the query.
    535   std::vector<AutofillServerFieldInfo> field_infos;
    536   UploadRequired upload_required;
    537   std::string experiment_id;
    538   AutofillQueryXmlParser parse_handler(&field_infos,
    539                                        &upload_required,
    540                                        &experiment_id);
    541   buzz::XmlParser parser(&parse_handler);
    542   parser.Parse(response_xml.c_str(), response_xml.length(), true);
    543   if (!parse_handler.succeeded())
    544     return;
    545 
    546   metric_logger.LogServerQueryMetric(AutofillMetrics::QUERY_RESPONSE_PARSED);
    547   metric_logger.LogServerExperimentIdForQuery(experiment_id);
    548 
    549   bool heuristics_detected_fillable_field = false;
    550   bool query_response_overrode_heuristics = false;
    551 
    552   // Copy the field types into the actual form.
    553   std::vector<AutofillServerFieldInfo>::iterator current_info =
    554       field_infos.begin();
    555   for (std::vector<FormStructure*>::const_iterator iter = forms.begin();
    556        iter != forms.end(); ++iter) {
    557     FormStructure* form = *iter;
    558     form->upload_required_ = upload_required;
    559     form->server_experiment_id_ = experiment_id;
    560 
    561     for (std::vector<AutofillField*>::iterator field = form->fields_.begin();
    562          field != form->fields_.end(); ++field) {
    563       if (form->ShouldSkipField(**field))
    564         continue;
    565 
    566       // In some cases *successful* response does not return all the fields.
    567       // Quit the update of the types then.
    568       if (current_info == field_infos.end())
    569         break;
    570 
    571       // UNKNOWN_TYPE is reserved for use by the client.
    572       DCHECK_NE(current_info->field_type, UNKNOWN_TYPE);
    573 
    574       ServerFieldType heuristic_type = (*field)->heuristic_type();
    575       if (heuristic_type != UNKNOWN_TYPE)
    576         heuristics_detected_fillable_field = true;
    577 
    578       (*field)->set_server_type(current_info->field_type);
    579       if (heuristic_type != (*field)->Type().GetStorableType())
    580         query_response_overrode_heuristics = true;
    581 
    582       // Copy default value into the field if available.
    583       if (!current_info->default_value.empty())
    584         (*field)->set_default_value(current_info->default_value);
    585 
    586       ++current_info;
    587     }
    588 
    589     form->UpdateAutofillCount();
    590     form->IdentifySections(false);
    591   }
    592 
    593   AutofillMetrics::ServerQueryMetric metric;
    594   if (query_response_overrode_heuristics) {
    595     if (heuristics_detected_fillable_field) {
    596       metric = AutofillMetrics::QUERY_RESPONSE_OVERRODE_LOCAL_HEURISTICS;
    597     } else {
    598       metric = AutofillMetrics::QUERY_RESPONSE_WITH_NO_LOCAL_HEURISTICS;
    599     }
    600   } else {
    601     metric = AutofillMetrics::QUERY_RESPONSE_MATCHED_LOCAL_HEURISTICS;
    602   }
    603   metric_logger.LogServerQueryMetric(metric);
    604 }
    605 
    606 // static
    607 void FormStructure::GetFieldTypePredictions(
    608     const std::vector<FormStructure*>& form_structures,
    609     std::vector<FormDataPredictions>* forms) {
    610   forms->clear();
    611   forms->reserve(form_structures.size());
    612   for (size_t i = 0; i < form_structures.size(); ++i) {
    613     FormStructure* form_structure = form_structures[i];
    614     FormDataPredictions form;
    615     form.data.name = form_structure->form_name_;
    616     form.data.method =
    617         ASCIIToUTF16((form_structure->method_ == POST) ? "POST" : "GET");
    618     form.data.origin = form_structure->source_url_;
    619     form.data.action = form_structure->target_url_;
    620     form.signature = form_structure->FormSignature();
    621     form.experiment_id = form_structure->server_experiment_id_;
    622 
    623     for (std::vector<AutofillField*>::const_iterator field =
    624              form_structure->fields_.begin();
    625          field != form_structure->fields_.end(); ++field) {
    626       form.data.fields.push_back(FormFieldData(**field));
    627 
    628       FormFieldDataPredictions annotated_field;
    629       annotated_field.signature = (*field)->FieldSignature();
    630       annotated_field.heuristic_type =
    631           AutofillType((*field)->heuristic_type()).ToString();
    632       annotated_field.server_type =
    633           AutofillType((*field)->server_type()).ToString();
    634       annotated_field.overall_type = (*field)->Type().ToString();
    635       form.fields.push_back(annotated_field);
    636     }
    637 
    638     forms->push_back(form);
    639   }
    640 }
    641 
    642 std::string FormStructure::FormSignature() const {
    643   std::string scheme(target_url_.scheme());
    644   std::string host(target_url_.host());
    645 
    646   // If target host or scheme is empty, set scheme and host of source url.
    647   // This is done to match the Toolbar's behavior.
    648   if (scheme.empty() || host.empty()) {
    649     scheme = source_url_.scheme();
    650     host = source_url_.host();
    651   }
    652 
    653   std::string form_string = scheme + "://" + host + "&" +
    654                             UTF16ToUTF8(form_name_) +
    655                             form_signature_field_names_;
    656 
    657   return Hash64Bit(form_string);
    658 }
    659 
    660 bool FormStructure::ShouldSkipField(const FormFieldData& field) const {
    661   return field.is_checkable;
    662 }
    663 
    664 bool FormStructure::IsAutofillable(bool require_method_post) const {
    665   if (autofill_count() < kRequiredAutofillFields)
    666     return false;
    667 
    668   return ShouldBeParsed(require_method_post);
    669 }
    670 
    671 void FormStructure::UpdateAutofillCount() {
    672   autofill_count_ = 0;
    673   for (std::vector<AutofillField*>::const_iterator iter = begin();
    674        iter != end(); ++iter) {
    675     AutofillField* field = *iter;
    676     if (field && field->IsFieldFillable())
    677       ++autofill_count_;
    678   }
    679 }
    680 
    681 bool FormStructure::ShouldBeParsed(bool require_method_post) const {
    682   if (active_field_count() < kRequiredAutofillFields)
    683     return false;
    684 
    685   // Rule out http(s)://*/search?...
    686   //  e.g. http://www.google.com/search?q=...
    687   //       http://search.yahoo.com/search?p=...
    688   if (target_url_.path() == "/search")
    689     return false;
    690 
    691   bool has_text_field = false;
    692   for (std::vector<AutofillField*>::const_iterator it = begin();
    693        it != end() && !has_text_field; ++it) {
    694     has_text_field |= (*it)->form_control_type != "select-one";
    695   }
    696   if (!has_text_field)
    697     return false;
    698 
    699   return !require_method_post || (method_ == POST);
    700 }
    701 
    702 bool FormStructure::ShouldBeCrowdsourced() const {
    703   return !has_author_specified_types_ && ShouldBeParsed(true);
    704 }
    705 
    706 void FormStructure::UpdateFromCache(const FormStructure& cached_form) {
    707   // Map from field signatures to cached fields.
    708   std::map<std::string, const AutofillField*> cached_fields;
    709   for (size_t i = 0; i < cached_form.field_count(); ++i) {
    710     const AutofillField* field = cached_form.field(i);
    711     cached_fields[field->FieldSignature()] = field;
    712   }
    713 
    714   for (std::vector<AutofillField*>::const_iterator iter = begin();
    715        iter != end(); ++iter) {
    716     AutofillField* field = *iter;
    717 
    718     std::map<std::string, const AutofillField*>::const_iterator
    719         cached_field = cached_fields.find(field->FieldSignature());
    720     if (cached_field != cached_fields.end()) {
    721       if (field->form_control_type != "select-one" &&
    722           field->value == cached_field->second->value) {
    723         // From the perspective of learning user data, text fields containing
    724         // default values are equivalent to empty fields.
    725         field->value = base::string16();
    726       }
    727 
    728       field->set_heuristic_type(cached_field->second->heuristic_type());
    729       field->set_server_type(cached_field->second->server_type());
    730     }
    731   }
    732 
    733   UpdateAutofillCount();
    734 
    735   server_experiment_id_ = cached_form.server_experiment_id();
    736 
    737   // The form signature should match between query and upload requests to the
    738   // server. On many websites, form elements are dynamically added, removed, or
    739   // rearranged via JavaScript between page load and form submission, so we
    740   // copy over the |form_signature_field_names_| corresponding to the query
    741   // request.
    742   DCHECK_EQ(cached_form.form_name_, form_name_);
    743   DCHECK_EQ(cached_form.source_url_, source_url_);
    744   DCHECK_EQ(cached_form.target_url_, target_url_);
    745   form_signature_field_names_ = cached_form.form_signature_field_names_;
    746 }
    747 
    748 void FormStructure::LogQualityMetrics(
    749     const AutofillMetrics& metric_logger,
    750     const base::TimeTicks& load_time,
    751     const base::TimeTicks& interaction_time,
    752     const base::TimeTicks& submission_time) const {
    753   std::string experiment_id = server_experiment_id();
    754   metric_logger.LogServerExperimentIdForUpload(experiment_id);
    755 
    756   size_t num_detected_field_types = 0;
    757   bool did_autofill_all_possible_fields = true;
    758   bool did_autofill_some_possible_fields = false;
    759   for (size_t i = 0; i < field_count(); ++i) {
    760     const AutofillField* field = this->field(i);
    761     metric_logger.LogQualityMetric(AutofillMetrics::FIELD_SUBMITTED,
    762                                    experiment_id);
    763 
    764     // No further logging for empty fields nor for fields where the entered data
    765     // does not appear to already exist in the user's stored Autofill data.
    766     const ServerFieldTypeSet& field_types = field->possible_types();
    767     DCHECK(!field_types.empty());
    768     if (field_types.count(EMPTY_TYPE) || field_types.count(UNKNOWN_TYPE))
    769       continue;
    770 
    771     // Similarly, no further logging for password fields.  Those are primarily
    772     // related to a different feature code path, and so make more sense to track
    773     // outside of this metric.
    774     if (field->form_control_type == "password")
    775       continue;
    776 
    777     ++num_detected_field_types;
    778     if (field->is_autofilled)
    779       did_autofill_some_possible_fields = true;
    780     else
    781       did_autofill_all_possible_fields = false;
    782 
    783     // Collapse field types that Chrome treats as identical, e.g. home and
    784     // billing address fields.
    785     ServerFieldTypeSet collapsed_field_types;
    786     for (ServerFieldTypeSet::const_iterator it = field_types.begin();
    787          it != field_types.end();
    788          ++it) {
    789       // Since we currently only support US phone numbers, the (city code + main
    790       // digits) number is almost always identical to the whole phone number.
    791       // TODO(isherman): Improve this logic once we add support for
    792       // international numbers.
    793       if (*it == PHONE_HOME_CITY_AND_NUMBER)
    794         collapsed_field_types.insert(PHONE_HOME_WHOLE_NUMBER);
    795       else
    796         collapsed_field_types.insert(AutofillType(*it).GetStorableType());
    797     }
    798 
    799     // Capture the field's type, if it is unambiguous.
    800     ServerFieldType field_type = UNKNOWN_TYPE;
    801     if (collapsed_field_types.size() == 1)
    802       field_type = *collapsed_field_types.begin();
    803 
    804     ServerFieldType heuristic_type =
    805         AutofillType(field->heuristic_type()).GetStorableType();
    806     ServerFieldType server_type =
    807         AutofillType(field->server_type()).GetStorableType();
    808     ServerFieldType predicted_type = field->Type().GetStorableType();
    809 
    810     // Log heuristic, server, and overall type quality metrics, independently of
    811     // whether the field was autofilled.
    812     if (heuristic_type == UNKNOWN_TYPE) {
    813       metric_logger.LogHeuristicTypePrediction(AutofillMetrics::TYPE_UNKNOWN,
    814                                                field_type, experiment_id);
    815     } else if (field_types.count(heuristic_type)) {
    816       metric_logger.LogHeuristicTypePrediction(AutofillMetrics::TYPE_MATCH,
    817                                                field_type, experiment_id);
    818     } else {
    819       metric_logger.LogHeuristicTypePrediction(AutofillMetrics::TYPE_MISMATCH,
    820                                                field_type, experiment_id);
    821     }
    822 
    823     if (server_type == NO_SERVER_DATA) {
    824       metric_logger.LogServerTypePrediction(AutofillMetrics::TYPE_UNKNOWN,
    825                                             field_type, experiment_id);
    826     } else if (field_types.count(server_type)) {
    827       metric_logger.LogServerTypePrediction(AutofillMetrics::TYPE_MATCH,
    828                                             field_type, experiment_id);
    829     } else {
    830       metric_logger.LogServerTypePrediction(AutofillMetrics::TYPE_MISMATCH,
    831                                             field_type, experiment_id);
    832     }
    833 
    834     if (predicted_type == UNKNOWN_TYPE) {
    835       metric_logger.LogOverallTypePrediction(AutofillMetrics::TYPE_UNKNOWN,
    836                                              field_type, experiment_id);
    837     } else if (field_types.count(predicted_type)) {
    838       metric_logger.LogOverallTypePrediction(AutofillMetrics::TYPE_MATCH,
    839                                              field_type, experiment_id);
    840     } else {
    841       metric_logger.LogOverallTypePrediction(AutofillMetrics::TYPE_MISMATCH,
    842                                              field_type, experiment_id);
    843     }
    844 
    845     // TODO(isherman): <select> fields don't support |is_autofilled()|, so we
    846     // have to skip them for the remaining metrics.
    847     if (field->form_control_type == "select-one")
    848       continue;
    849 
    850     if (field->is_autofilled) {
    851       metric_logger.LogQualityMetric(AutofillMetrics::FIELD_AUTOFILLED,
    852                                      experiment_id);
    853     } else {
    854       metric_logger.LogQualityMetric(AutofillMetrics::FIELD_NOT_AUTOFILLED,
    855                                      experiment_id);
    856 
    857       if (heuristic_type == UNKNOWN_TYPE) {
    858         metric_logger.LogQualityMetric(
    859             AutofillMetrics::NOT_AUTOFILLED_HEURISTIC_TYPE_UNKNOWN,
    860             experiment_id);
    861       } else if (field_types.count(heuristic_type)) {
    862         metric_logger.LogQualityMetric(
    863             AutofillMetrics::NOT_AUTOFILLED_HEURISTIC_TYPE_MATCH,
    864             experiment_id);
    865       } else {
    866         metric_logger.LogQualityMetric(
    867             AutofillMetrics::NOT_AUTOFILLED_HEURISTIC_TYPE_MISMATCH,
    868             experiment_id);
    869       }
    870 
    871       if (server_type == NO_SERVER_DATA) {
    872         metric_logger.LogQualityMetric(
    873             AutofillMetrics::NOT_AUTOFILLED_SERVER_TYPE_UNKNOWN,
    874             experiment_id);
    875       } else if (field_types.count(server_type)) {
    876         metric_logger.LogQualityMetric(
    877             AutofillMetrics::NOT_AUTOFILLED_SERVER_TYPE_MATCH,
    878             experiment_id);
    879       } else {
    880         metric_logger.LogQualityMetric(
    881             AutofillMetrics::NOT_AUTOFILLED_SERVER_TYPE_MISMATCH,
    882             experiment_id);
    883       }
    884     }
    885   }
    886 
    887   if (num_detected_field_types < kRequiredAutofillFields) {
    888     metric_logger.LogUserHappinessMetric(
    889         AutofillMetrics::SUBMITTED_NON_FILLABLE_FORM);
    890   } else {
    891     if (did_autofill_all_possible_fields) {
    892       metric_logger.LogUserHappinessMetric(
    893           AutofillMetrics::SUBMITTED_FILLABLE_FORM_AUTOFILLED_ALL);
    894     } else if (did_autofill_some_possible_fields) {
    895       metric_logger.LogUserHappinessMetric(
    896           AutofillMetrics::SUBMITTED_FILLABLE_FORM_AUTOFILLED_SOME);
    897     } else {
    898       metric_logger.LogUserHappinessMetric(
    899           AutofillMetrics::SUBMITTED_FILLABLE_FORM_AUTOFILLED_NONE);
    900     }
    901 
    902     // Unlike the other times, the |submission_time| should always be available.
    903     DCHECK(!submission_time.is_null());
    904 
    905     // The |load_time| might be unset, in the case that the form was dynamically
    906     // added to the DOM.
    907     if (!load_time.is_null()) {
    908       // Submission should always chronologically follow form load.
    909       DCHECK(submission_time > load_time);
    910       base::TimeDelta elapsed = submission_time - load_time;
    911       if (did_autofill_some_possible_fields)
    912         metric_logger.LogFormFillDurationFromLoadWithAutofill(elapsed);
    913       else
    914         metric_logger.LogFormFillDurationFromLoadWithoutAutofill(elapsed);
    915     }
    916 
    917     // The |interaction_time| might be unset, in the case that the user
    918     // submitted a blank form.
    919     if (!interaction_time.is_null()) {
    920       // Submission should always chronologically follow interaction.
    921       DCHECK(submission_time > interaction_time);
    922       base::TimeDelta elapsed = submission_time - interaction_time;
    923       if (did_autofill_some_possible_fields) {
    924         metric_logger.LogFormFillDurationFromInteractionWithAutofill(elapsed);
    925       } else {
    926         metric_logger.LogFormFillDurationFromInteractionWithoutAutofill(
    927             elapsed);
    928       }
    929     }
    930   }
    931 }
    932 
    933 const AutofillField* FormStructure::field(size_t index) const {
    934   if (index >= fields_.size()) {
    935     NOTREACHED();
    936     return NULL;
    937   }
    938 
    939   return fields_[index];
    940 }
    941 
    942 AutofillField* FormStructure::field(size_t index) {
    943   return const_cast<AutofillField*>(
    944       static_cast<const FormStructure*>(this)->field(index));
    945 }
    946 
    947 size_t FormStructure::field_count() const {
    948   return fields_.size();
    949 }
    950 
    951 size_t FormStructure::active_field_count() const {
    952   return active_field_count_;
    953 }
    954 
    955 std::string FormStructure::server_experiment_id() const {
    956   return server_experiment_id_;
    957 }
    958 
    959 FormData FormStructure::ToFormData() const {
    960   // |data.user_submitted| will always be false.
    961   FormData data;
    962   data.name = form_name_;
    963   data.origin = source_url_;
    964   data.action = target_url_;
    965   data.method = ASCIIToUTF16(method_ == POST ? "POST" : "GET");
    966 
    967   for (size_t i = 0; i < fields_.size(); ++i) {
    968     data.fields.push_back(FormFieldData(*fields_[i]));
    969   }
    970 
    971   return data;
    972 }
    973 
    974 bool FormStructure::operator==(const FormData& form) const {
    975   // TODO(jhawkins): Is this enough to differentiate a form?
    976   if (form_name_ == form.name &&
    977       source_url_ == form.origin &&
    978       target_url_ == form.action) {
    979     return true;
    980   }
    981 
    982   // TODO(jhawkins): Compare field names, IDs and labels once we have labels
    983   // set up.
    984 
    985   return false;
    986 }
    987 
    988 bool FormStructure::operator!=(const FormData& form) const {
    989   return !operator==(form);
    990 }
    991 
    992 std::string FormStructure::Hash64Bit(const std::string& str) {
    993   std::string hash_bin = base::SHA1HashString(str);
    994   DCHECK_EQ(20U, hash_bin.length());
    995 
    996   uint64 hash64 = (((static_cast<uint64>(hash_bin[0])) & 0xFF) << 56) |
    997                   (((static_cast<uint64>(hash_bin[1])) & 0xFF) << 48) |
    998                   (((static_cast<uint64>(hash_bin[2])) & 0xFF) << 40) |
    999                   (((static_cast<uint64>(hash_bin[3])) & 0xFF) << 32) |
   1000                   (((static_cast<uint64>(hash_bin[4])) & 0xFF) << 24) |
   1001                   (((static_cast<uint64>(hash_bin[5])) & 0xFF) << 16) |
   1002                   (((static_cast<uint64>(hash_bin[6])) & 0xFF) << 8) |
   1003                    ((static_cast<uint64>(hash_bin[7])) & 0xFF);
   1004 
   1005   return base::Uint64ToString(hash64);
   1006 }
   1007 
   1008 bool FormStructure::EncodeFormRequest(
   1009     FormStructure::EncodeRequestType request_type,
   1010     buzz::XmlElement* encompassing_xml_element) const {
   1011   if (!field_count())  // Nothing to add.
   1012     return false;
   1013 
   1014   // Some badly formatted web sites repeat fields - limit number of fields to
   1015   // 48, which is far larger than any valid form and XML still fits into 2K.
   1016   // Do not send requests for forms with more than this many fields, as they are
   1017   // near certainly not valid/auto-fillable.
   1018   const size_t kMaxFieldsOnTheForm = 48;
   1019   if (field_count() > kMaxFieldsOnTheForm)
   1020     return false;
   1021 
   1022   // Add the child nodes for the form fields.
   1023   for (size_t index = 0; index < field_count(); ++index) {
   1024     const AutofillField* field = fields_[index];
   1025     switch (request_type) {
   1026       case FormStructure::UPLOAD:
   1027         EncodeFieldForUpload(*field, encompassing_xml_element);
   1028         break;
   1029       case FormStructure::QUERY:
   1030         if (ShouldSkipField(*field))
   1031           continue;
   1032         EncodeFieldForQuery(*field, encompassing_xml_element);
   1033         break;
   1034       case FormStructure::FIELD_ASSIGNMENTS:
   1035         EncodeFieldForFieldAssignments(*field, encompassing_xml_element);
   1036         break;
   1037     }
   1038   }
   1039   return true;
   1040 }
   1041 
   1042 void FormStructure::ParseFieldTypesFromAutocompleteAttributes(
   1043     bool* found_types,
   1044     bool* found_sections) {
   1045   const std::string kDefaultSection = "-default";
   1046 
   1047   *found_types = false;
   1048   *found_sections = false;
   1049   for (std::vector<AutofillField*>::iterator it = fields_.begin();
   1050        it != fields_.end(); ++it) {
   1051     AutofillField* field = *it;
   1052 
   1053     // To prevent potential section name collisions, add a default suffix for
   1054     // other fields.  Without this, 'autocomplete' attribute values
   1055     // "section--shipping street-address" and "shipping street-address" would be
   1056     // parsed identically, given the section handling code below.  We do this
   1057     // before any validation so that fields with invalid attributes still end up
   1058     // in the default section.  These default section names will be overridden
   1059     // by subsequent heuristic parsing steps if there are no author-specified
   1060     // section names.
   1061     field->set_section(kDefaultSection);
   1062 
   1063     // Canonicalize the attribute value by trimming whitespace, collapsing
   1064     // non-space characters (e.g. tab) to spaces, and converting to lowercase.
   1065     std::string autocomplete_attribute =
   1066         CollapseWhitespaceASCII(field->autocomplete_attribute, false);
   1067     autocomplete_attribute = StringToLowerASCII(autocomplete_attribute);
   1068 
   1069     // The autocomplete attribute is overloaded: it can specify either a field
   1070     // type hint or whether autocomplete should be enabled at all.  Ignore the
   1071     // latter type of attribute value.
   1072     if (autocomplete_attribute.empty() ||
   1073         autocomplete_attribute == "on" ||
   1074         autocomplete_attribute == "off") {
   1075       continue;
   1076     }
   1077 
   1078     // Any other value, even it is invalid, is considered to be a type hint.
   1079     // This allows a website's author to specify an attribute like
   1080     // autocomplete="other" on a field to disable all Autofill heuristics for
   1081     // the form.
   1082     *found_types = true;
   1083 
   1084     // Tokenize the attribute value.  Per the spec, the tokens are parsed in
   1085     // reverse order.
   1086     std::vector<std::string> tokens;
   1087     Tokenize(autocomplete_attribute, " ", &tokens);
   1088 
   1089     // The final token must be the field type.
   1090     // If it is not one of the known types, abort.
   1091     DCHECK(!tokens.empty());
   1092     std::string field_type_token = tokens.back();
   1093     tokens.pop_back();
   1094     HtmlFieldType field_type =
   1095         FieldTypeFromAutocompleteAttributeValue(field_type_token, *field);
   1096     if (field_type == HTML_TYPE_UNKNOWN)
   1097       continue;
   1098 
   1099     // The preceding token, if any, may be a type hint.
   1100     if (!tokens.empty() && IsContactTypeHint(tokens.back())) {
   1101       // If it is, it must match the field type; otherwise, abort.
   1102       // Note that an invalid token invalidates the entire attribute value, even
   1103       // if the other tokens are valid.
   1104       if (!ContactTypeHintMatchesFieldType(tokens.back(), field_type))
   1105         continue;
   1106 
   1107       // Chrome Autofill ignores these type hints.
   1108       tokens.pop_back();
   1109     }
   1110 
   1111     // The preceding token, if any, may be a fixed string that is either
   1112     // "shipping" or "billing".  Chrome Autofill treats these as implicit
   1113     // section name suffixes.
   1114     DCHECK_EQ(kDefaultSection, field->section());
   1115     std::string section = field->section();
   1116     HtmlFieldMode mode = HTML_MODE_NONE;
   1117     if (!tokens.empty()) {
   1118       if (tokens.back() == kShippingMode)
   1119         mode = HTML_MODE_SHIPPING;
   1120       else if (tokens.back() == kBillingMode)
   1121         mode = HTML_MODE_BILLING;
   1122     }
   1123 
   1124     if (mode != HTML_MODE_NONE) {
   1125       section = "-" + tokens.back();
   1126       tokens.pop_back();
   1127     }
   1128 
   1129     // The preceding token, if any, may be a named section.
   1130     const std::string kSectionPrefix = "section-";
   1131     if (!tokens.empty() &&
   1132         StartsWithASCII(tokens.back(), kSectionPrefix, true)) {
   1133       // Prepend this section name to the suffix set in the preceding block.
   1134       section = tokens.back().substr(kSectionPrefix.size()) + section;
   1135       tokens.pop_back();
   1136     }
   1137 
   1138     // No other tokens are allowed.  If there are any remaining, abort.
   1139     if (!tokens.empty())
   1140       continue;
   1141 
   1142     if (section != kDefaultSection) {
   1143       *found_sections = true;
   1144       field->set_section(section);
   1145     }
   1146 
   1147     // No errors encountered while parsing!
   1148     // Update the |field|'s type based on what was parsed from the attribute.
   1149     field->SetHtmlType(field_type, mode);
   1150   }
   1151 }
   1152 
   1153 void FormStructure::IdentifySections(bool has_author_specified_sections) {
   1154   if (fields_.empty())
   1155     return;
   1156 
   1157   if (!has_author_specified_sections) {
   1158     // Name sections after the first field in the section.
   1159     base::string16 current_section = fields_.front()->unique_name();
   1160 
   1161     // Keep track of the types we've seen in this section.
   1162     std::set<ServerFieldType> seen_types;
   1163     ServerFieldType previous_type = UNKNOWN_TYPE;
   1164 
   1165     for (std::vector<AutofillField*>::iterator field = fields_.begin();
   1166          field != fields_.end(); ++field) {
   1167       const ServerFieldType current_type = (*field)->Type().GetStorableType();
   1168 
   1169       bool already_saw_current_type = seen_types.count(current_type) > 0;
   1170 
   1171       // Forms often ask for multiple phone numbers -- e.g. both a daytime and
   1172       // evening phone number.  Our phone number detection is also generally a
   1173       // little off.  Hence, ignore this field type as a signal here.
   1174       if (AutofillType(current_type).group() == PHONE_HOME)
   1175         already_saw_current_type = false;
   1176 
   1177       // Some forms have adjacent fields of the same type.  Two common examples:
   1178       //  * Forms with two email fields, where the second is meant to "confirm"
   1179       //    the first.
   1180       //  * Forms with a <select> menu for states in some countries, and a
   1181       //    freeform <input> field for states in other countries.  (Usually,
   1182       //    only one of these two will be visible for any given choice of
   1183       //    country.)
   1184       // Generally, adjacent fields of the same type belong in the same logical
   1185       // section.
   1186       if (current_type == previous_type)
   1187         already_saw_current_type = false;
   1188 
   1189       previous_type = current_type;
   1190 
   1191       if (current_type != UNKNOWN_TYPE && already_saw_current_type) {
   1192         // We reached the end of a section, so start a new section.
   1193         seen_types.clear();
   1194         current_section = (*field)->unique_name();
   1195       }
   1196 
   1197       seen_types.insert(current_type);
   1198       (*field)->set_section(UTF16ToUTF8(current_section));
   1199     }
   1200   }
   1201 
   1202   // Ensure that credit card and address fields are in separate sections.
   1203   // This simplifies the section-aware logic in autofill_manager.cc.
   1204   for (std::vector<AutofillField*>::iterator field = fields_.begin();
   1205        field != fields_.end(); ++field) {
   1206     FieldTypeGroup field_type_group = (*field)->Type().group();
   1207     if (field_type_group == CREDIT_CARD)
   1208       (*field)->set_section((*field)->section() + "-cc");
   1209     else
   1210       (*field)->set_section((*field)->section() + "-default");
   1211   }
   1212 }
   1213 
   1214 }  // namespace autofill
   1215