[Autofill] Always show available data when encountering autocomplete attributes

components/autofill/content/renderer/form_cache.cc

Index: components/autofill/content/renderer/form_cache.cc
diff --git a/components/autofill/content/renderer/form_cache.cc b/components/autofill/content/renderer/form_cache.cc
index 81ddf83574d53c6727ecbf50714fb6ef93bf38c9..c2f52ea0c4d1b9633de5520e8f708e04cc2ddb1d 100644
--- a/components/autofill/content/renderer/form_cache.cc
+++ b/components/autofill/content/renderer/form_cache.cc
@@ -64,8 +64,7 @@ void LogDeprecationMessages(const WebFormControlElement& element) {
 // is imposed by WebFormElementToFormData().

[Evan Stade, 2015/11/04 17:15:18]

I think this comment needs further updating because I can't grasp the logic of
why you require there to be control elements in order to ignore the form

[sebsg, 2015/11/10 19:04:50]

As I read the code more I realized that num_editable_elements is a subset of
num_control_elements (the editable ones) which is really the number of
autofillable fields. Talked to isherman@ and it was used with has_skipped_forms
https://chromiumcodereview.appspot.com/13831013 which is no longer there. So I
removed it. DO you know of a reason why it would still be useful?

 bool ShouldIgnoreForm(size_t num_editable_elements,
                       size_t num_control_elements) {
-  return (num_editable_elements < kRequiredAutofillFields &&
-          num_control_elements > 0);

[Evan Stade, 2015/11/04 17:15:18]

prefer this way of checking against 0 rather than implicit cast to bool

[sebsg, 2015/11/10 19:04:50]

Done.

+  return (!num_editable_elements && num_control_elements);

[Evan Stade, 2015/11/04 17:15:18]

nit: remove excess parens

[sebsg, 2015/11/10 19:04:50]

Done.

 }
 
 }  // namespace
@@ -117,8 +116,7 @@ std::vector<FormData> FormCache::ExtractNewForms() {
     if (num_fields_seen > form_util::kMaxParseableFields)
       return forms;
 
-    if (form.fields.size() >= kRequiredAutofillFields &&
-        !ContainsKey(parsed_forms_, form)) {
+    if (!ContainsKey(parsed_forms_, form) && IsFormInteresting(form)) {
       for (auto it = parsed_forms_.begin(); it != parsed_forms_.end(); ++it) {
         if (it->SameFormAs(form)) {
           parsed_forms_.erase(it);
@@ -155,8 +153,8 @@ std::vector<FormData> FormCache::ExtractNewForms() {
   if (num_fields_seen > form_util::kMaxParseableFields)
     return forms;
 
-  if (synthetic_form.fields.size() >= kRequiredAutofillFields &&
-      !parsed_forms_.count(synthetic_form)) {
+  if (!parsed_forms_.count(synthetic_form) &&
+      IsFormInteresting(synthetic_form)) {
     SaveInitialValues(control_elements);
     forms.push_back(synthetic_form);
     parsed_forms_.insert(synthetic_form);
@@ -305,6 +303,23 @@ bool FormCache::ShowPredictions(const FormDataPredictions& form) {
   return true;
 }
 
+// static
+bool FormCache::IsFormInteresting(FormData form) {
+  if (form.fields.empty())
+    return false;
+
+  // If the form has at least one field with an autocomplete attribute,
+  // autocomplete suggestions will be shown.

[Evan Stade, 2015/11/04 17:15:18]

this comment is misleading, we don't know if suggestions will be shown or not

[sebsg, 2015/11/10 19:04:50]

Done.

+  for (auto field : form.fields) {
+    if (!field.autocomplete_attribute.empty())
+      return true;
+  }
+
+  // If there are no autocomplete attributes, the form needs to have at least
+  // the required number of fields to be a candidate for autofill.
+  return form.fields.size() >= kRequiredAutofillFields;
+}
+
 size_t FormCache::ScanFormControlElements(
     const std::vector<WebFormControlElement>& control_elements,
     bool log_deprecation_messages) {