Don't upload "null" to the Sync server for empty federation_url.

components/password_manager/core/browser/login_database.cc

 // Copyright 2014 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/password_manager/core/browser/login_database.h"
 
 #include <stddef.h>
 #include <stdint.h>
 #include <algorithm>
 #include <limits>
@@ skipping 123 matching lines @@
               usernames_pickle.size());
   s->BindInt(COLUMN_TIMES_USED, form.times_used);
   base::Pickle form_data_pickle;
   autofill::SerializeFormData(form.form_data, &form_data_pickle);
   s->BindBlob(COLUMN_FORM_DATA,
               form_data_pickle.data(),
               form_data_pickle.size());
   s->BindInt64(COLUMN_DATE_SYNCED, form.date_synced.ToInternalValue());
   s->BindString16(COLUMN_DISPLAY_NAME, form.display_name);
   s->BindString(COLUMN_ICON_URL, form.icon_url.spec());
-  s->BindString(COLUMN_FEDERATION_URL, form.federation_origin.Serialize());
+  s->BindString(COLUMN_FEDERATION_URL,
+                form.federation_origin.unique()

[markusheintz_, 2016/03/09 18:02:59]

opt: Add acomment describing why or simply referencing the bug.

[vasilii, 2016/03/09 18:11:20]

Done.

+                    ? std::string()
+                    : form.federation_origin.Serialize());
   s->BindInt(COLUMN_SKIP_ZERO_CLICK, form.skip_zero_click);
   s->BindInt(COLUMN_GENERATION_UPLOAD_STATUS, form.generation_upload_status);
 }
 
 void AddCallback(int err, sql::Statement* /*stmt*/) {
   if (err == 19 /*SQLITE_CONSTRAINT*/)
     DLOG(WARNING) << "LoginDatabase::AddLogin updated an existing form";
 }
 
 bool DoesMatchConstraints(const PasswordForm& form) {
@@ skipping 1190 matching lines @@
     UMA_HISTOGRAM_ENUMERATION("PasswordManager.PslDomainMatchTriggering",
                               psl_domain_match_metric, PSL_DOMAIN_MATCH_COUNT);
   }
 
   if (!statement->Succeeded())
     return false;
   return true;
 }
 
 }  // namespace password_manager