[Password Manager] Modified to support saving passwords on forms without username fields.

components/autofill/core/common/password_form_fill_data.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/common/password_form_fill_data.h"
 
 #include "base/logging.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/autofill/core/common/form_field_data.h"
 
@@ skipping 21 matching lines @@
 void InitPasswordFormFillData(
     const PasswordForm& form_on_page,
     const PasswordFormMap& matches,
     const PasswordForm* const preferred_match,
     bool wait_for_username_before_autofill,
     bool enable_other_possible_usernames,
     PasswordFormFillData* result) {
   // Note that many of the |FormFieldData| members are not initialized for
   // |username_field| and |password_field| because they are currently not used
   // by the password autocomplete code.
-  FormFieldData username_field;
-  username_field.name = form_on_page.username_element;
-  username_field.value = preferred_match->username_value;
+  if (!form_on_page.username_element.empty()) {
+    FormFieldData username_field;
+    username_field.name = form_on_page.username_element;
+    username_field.value = preferred_match->username_value;
+    result->basic_data.fields.push_back(username_field);
+  }
+
   FormFieldData password_field;
   password_field.name = form_on_page.password_element;
   password_field.value = preferred_match->password_value;
   password_field.form_control_type = "password";
+  result->basic_data.fields.push_back(password_field);
 
   // Fill basic form data.
   result->basic_data.origin = form_on_page.origin;
   result->basic_data.action = form_on_page.action;
-  result->basic_data.fields.push_back(username_field);
-  result->basic_data.fields.push_back(password_field);
   result->wait_for_username = wait_for_username_before_autofill;
-
   result->preferred_realm = preferred_match->original_signon_realm;
 
   // Copy additional username/value pairs.
   PasswordFormMap::const_iterator iter;
   for (iter = matches.begin(); iter != matches.end(); iter++) {
     if (iter->second != preferred_match) {
       PasswordAndRealm value;
       value.password = iter->second->password_value;
       value.realm = iter->second->original_signon_realm;
       result->additional_logins[iter->first] = value;
     }
     if (enable_other_possible_usernames &&
         !iter->second->other_possible_usernames.empty()) {
       // Note that there may be overlap between other_possible_usernames and
       // other saved usernames or with other other_possible_usernames. For now
       // we will ignore this overlap as it should be a rare occurence. We may
       // want to revisit this in the future.
       UsernamesCollectionKey key;
       key.username = iter->first;
       key.password = iter->second->password_value;
       key.realm = iter->second->original_signon_realm;
       result->other_possible_usernames[key] =
           iter->second->other_possible_usernames;
     }
   }
 }
 
 }  // namespace autofill