Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/modules/webdatabase/SQLTransactionBackendSync.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 60 matching lines @@
 
 PassRefPtr<SQLResultSet> SQLTransactionBackendSync::executeSQL(const String& sqlStatement, const Vector<SQLValue>& arguments, ExceptionState& exceptionState)
 {
     ASSERT(m_database->executionContext()->isContextThread());
 
     m_database->setLastErrorMessage("");
 
     if (!m_database->opened()) {
         m_database->setLastErrorMessage("cannot executeSQL because the database is not open");
         exceptionState.throwDOMException(UnknownError, SQLError::unknownErrorMessage);
-        return 0;
+        return nullptr;
     }
 
     if (m_hasVersionMismatch) {
         m_database->setLastErrorMessage("cannot executeSQL because there is a version mismatch");
         exceptionState.throwDOMException(VersionError, SQLError::versionErrorMessage);
-        return 0;
+        return nullptr;
     }
 
     if (sqlStatement.isEmpty())
-        return 0;
+        return nullptr;
 
     int permissions = DatabaseAuthorizer::ReadWriteMask;
     if (!m_database->databaseContext()->allowDatabaseAccess())
         permissions |= DatabaseAuthorizer::NoAccessMask;
     else if (m_readOnly)
         permissions |= DatabaseAuthorizer::ReadOnlyMask;
 
     SQLStatementSync statement(sqlStatement, arguments, permissions);
 
     m_database->resetAuthorizer();
     bool retryStatement = true;
     RefPtr<SQLResultSet> resultSet;
     while (retryStatement) {
         retryStatement = false;
         resultSet = statement.execute(m_database.get(), exceptionState);
         if (!resultSet) {
             if (m_sqliteTransaction->wasRolledBackBySqlite())
-                return 0;
+                return nullptr;
 
             if (exceptionState.code() == QuotaExceededError) {
                 if (m_transactionClient->didExceedQuota(database())) {
                     exceptionState.clearException();
                     retryStatement = true;
                 } else {
                     m_database->setLastErrorMessage("there was not enough remaining storage space");
-                    return 0;
+                    return nullptr;
                 }
             }
         }
     }
 
     if (m_database->lastActionChangedDatabase())
         m_modifiedDatabase = true;
 
     return resultSet.release();
 }
@@ skipping 108 matching lines @@
     if (m_sqliteTransaction) {
         m_sqliteTransaction->rollback();
         m_sqliteTransaction.clear();
     }
     m_database->enableAuthorizer();
 
     ASSERT(!m_database->sqliteDatabase().transactionInProgress());
 }
 
 } // namespace WebCore