diff --git a/core/includes/install.inc b/core/includes/install.inc
index c308a2d..b73f554 100644
--- a/core/includes/install.inc
+++ b/core/includes/install.inc
@@ -1103,6 +1103,8 @@ function db_run_tasks($driver) {
  *
  * @param $driver
  *   The name of the driver.
+ *
+ * @return \Drupal\Core\Database\Install\Tasks
  */
 function db_installer_object($driver) {
   // We cannot use Database::getConnection->getDriverClass() here, because
diff --git a/core/lib/Drupal/Core/Database/Driver/mysql/Install/Tasks.php b/core/lib/Drupal/Core/Database/Driver/mysql/Install/Tasks.php
index 1d04883..5a1f1ae 100644
--- a/core/lib/Drupal/Core/Database/Driver/mysql/Install/Tasks.php
+++ b/core/lib/Drupal/Core/Database/Driver/mysql/Install/Tasks.php
@@ -24,22 +24,21 @@ class Tasks extends InstallTasks {
   protected $pdoDriver = 'mysql';
 
   /**
-   * Returns a human-readable name string for MySQL and equivalent databases.
+   * {@inheritdoc}
    */
   public function name() {
     return t('MySQL, MariaDB, Percona Server, or equivalent');
   }
 
   /**
-   * Returns the minimum version for MySQL.
+   * {@inheritdoc}
    */
   public function minimumVersion() {
     return '5.0.15';
   }
 
   /**
-   * Check database connection and attempt to create database if the database is
-   * missing.
+   * {@inheritdoc}
    */
   protected function connect() {
     try {
diff --git a/core/lib/Drupal/Core/Database/Driver/pgsql/Install/Tasks.php b/core/lib/Drupal/Core/Database/Driver/pgsql/Install/Tasks.php
index bb30901..481c484 100644
--- a/core/lib/Drupal/Core/Database/Driver/pgsql/Install/Tasks.php
+++ b/core/lib/Drupal/Core/Database/Driver/pgsql/Install/Tasks.php
@@ -13,11 +13,18 @@
 use Drupal\Core\Database\DatabaseNotFoundException;
 
 /**
- * PostgreSQL specific install functions
+ * Specifies installation tasks for PostgreSQL databases.
  */
 class Tasks extends InstallTasks {
+
+  /**
+   * {@inheritdoc}
+   */
   protected $pdoDriver = 'pgsql';
 
+  /**
+   * Constructs a \Drupal\Core\Database\Driver\pgsql\Install\Tasks object.
+   */
   public function __construct() {
     $this->tasks[] = array(
       'function' => 'checkEncoding',
@@ -33,17 +40,22 @@ public function __construct() {
     );
   }
 
+  /**
+   * {@inheritdoc}
+   */
   public function name() {
     return t('PostgreSQL');
   }
 
+  /**
+   * {@inheritdoc}
+   */
   public function minimumVersion() {
     return '8.3';
   }
 
   /**
-   * Check database connection and attempt to create database if the database is
-   * missing.
+   * {@inheritdoc}
    */
   protected function connect() {
     try {
@@ -126,7 +138,7 @@ protected function checkEncoding() {
    *
    * Unserializing does not work on Postgresql 9 when bytea_output is 'hex'.
    */
-  function checkBinaryOutput() {
+  public function checkBinaryOutput() {
     // PostgreSQL < 9 doesn't support bytea_output, so verify we are running
     // at least PostgreSQL 9.
     $database_connection = Database::getConnection();
@@ -178,7 +190,7 @@ protected function checkBinaryOutputSuccess() {
   /**
    * Make PostgreSQL Drupal friendly.
    */
-  function initializeDatabase() {
+  public function initializeDatabase() {
     // We create some functions using global names instead of prefixing them
     // like we do with table names. This is so that we don't double up if more
     // than one instance of Drupal is running on a single database. We therefore
diff --git a/core/lib/Drupal/Core/Database/Driver/sqlite/Install/Tasks.php b/core/lib/Drupal/Core/Database/Driver/sqlite/Install/Tasks.php
index 1079688..08aa250 100644
--- a/core/lib/Drupal/Core/Database/Driver/sqlite/Install/Tasks.php
+++ b/core/lib/Drupal/Core/Database/Driver/sqlite/Install/Tasks.php
@@ -12,22 +12,34 @@
 use Drupal\Core\Database\DatabaseNotFoundException;
 use Drupal\Core\Database\Install\Tasks as InstallTasks;
 
+/**
+ * Specifies installation tasks for SQLite databases.
+ */
 class Tasks extends InstallTasks {
+
+  /**
+   * {@inheritdoc}
+   */
   protected $pdoDriver = 'sqlite';
 
+  /**
+   * {@inheritdoc}
+   */
   public function name() {
     return t('SQLite');
   }
 
   /**
-   * Minimum engine version.
-   *
-   * @todo Consider upping to 3.6.8 in Drupal 8 to get SAVEPOINT support.
+   * {@inheritdoc}
    */
   public function minimumVersion() {
+    // @todo Consider upping to 3.6.8 in Drupal 8 to get SAVEPOINT support.
     return '3.3.7';
   }
 
+  /**
+   * {@inheritdoc}
+   */
   public function getFormOptions($database) {
     $form = parent::getFormOptions($database);
 
@@ -43,8 +55,7 @@ public function getFormOptions($database) {
   }
 
   /**
-   * Check database connection and attempt to create database if the database is
-   * missing.
+   * {@inheritdoc}
    */
   protected function connect() {
     try {
diff --git a/core/lib/Drupal/Core/Database/Install/Tasks.php b/core/lib/Drupal/Core/Database/Install/Tasks.php
index d46251b..d16cc70 100644
--- a/core/lib/Drupal/Core/Database/Install/Tasks.php
+++ b/core/lib/Drupal/Core/Database/Install/Tasks.php
@@ -19,6 +19,13 @@
 abstract class Tasks {
 
   /**
+   * The name of the PDO driver this database type requires.
+   *
+   * @var string
+   */
+  protected $pdoDriver;
+
+  /**
    * Structure that describes each task to run.
    *
    * @var array