diff --git a/core/modules/migrate_drupal_ui/src/MigrateMessageCapture.php b/core/modules/migrate_drupal_ui/src/Batch/MigrateMessageCapture.php
similarity index 94%
rename from core/modules/migrate_drupal_ui/src/MigrateMessageCapture.php
rename to core/modules/migrate_drupal_ui/src/Batch/MigrateMessageCapture.php
index 72e1ace..efa0a57 100644
--- a/core/modules/migrate_drupal_ui/src/MigrateMessageCapture.php
+++ b/core/modules/migrate_drupal_ui/src/Batch/MigrateMessageCapture.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Drupal\migrate_drupal_ui;
+namespace Drupal\migrate_drupal_ui\Batch;
 
 use Drupal\migrate\MigrateMessageInterface;
 
diff --git a/core/modules/migrate_drupal_ui/src/Batch/MigrateUpgradeBatchBase.php b/core/modules/migrate_drupal_ui/src/Batch/MigrateUpgradeBatchBase.php
new file mode 100644
index 0000000..f80f329
--- /dev/null
+++ b/core/modules/migrate_drupal_ui/src/Batch/MigrateUpgradeBatchBase.php
@@ -0,0 +1,116 @@
+<?php
+
+namespace Drupal\migrate_drupal_ui\Batch;
+
+use Drupal\migrate\Plugin\MigrationInterface;
+use Drupal\migrate\Event\MigrateIdMapMessageEvent;
+use Drupal\migrate\Event\MigrateMapDeleteEvent;
+use Drupal\migrate\Event\MigrateMapSaveEvent;
+use Drupal\migrate\Event\MigratePostRowSaveEvent;
+use Drupal\migrate\Event\MigrateRowDeleteEvent;
+
+/**
+ * Runs a single migration batch.
+ */
+abstract class MigrateUpgradeBatchBase {
+
+  /**
+   * Maximum number of previous messages to display.
+   */
+  const MESSAGE_LENGTH = 20;
+
+  /**
+   * The processed items for one batch of a given migration.
+   *
+   * @var int
+   */
+  static $numProcessed = 0;
+
+  /**
+   * Ensure we only add the listeners once per request.
+   *
+   * @var bool
+   */
+  protected static $listenersAdded = FALSE;
+
+  /**
+   * The maximum length in seconds to allow processing in a request.
+   *
+   * @see self::run()
+   *
+   * @var int
+   */
+  protected static $maxExecTime;
+
+  /**
+   * MigrateMessage instance to capture messages during the migration process.
+   *
+   * @var \Drupal\migrate_drupal_ui\Batch\MigrateMessageCapture
+   */
+  protected static $messages;
+
+  /**
+   * Reacts to item import.
+   *
+   * @param \Drupal\migrate\Event\MigratePostRowSaveEvent $event
+   *   The post-save event.
+   */
+  public static function onPostRowSave(MigratePostRowSaveEvent $event) {
+    // We want to interrupt this batch and start a fresh one.
+    if ((time() - REQUEST_TIME) > static::$maxExecTime) {
+      $event->getMigration()->interruptMigration(MigrationInterface::RESULT_INCOMPLETE);
+    }
+  }
+
+  /**
+   * Reacts to item deletion.
+   *
+   * @param \Drupal\migrate\Event\MigrateRowDeleteEvent $event
+   *   The post-save event.
+   */
+  public static function onPostRowDelete(MigrateRowDeleteEvent $event) {
+    // We want to interrupt this batch and start a fresh one.
+    if ((time() - REQUEST_TIME) > static::$maxExecTime) {
+      $event->getMigration()->interruptMigration(MigrationInterface::RESULT_INCOMPLETE);
+    }
+  }
+
+  /**
+   * Counts up any map save events.
+   *
+   * @param \Drupal\migrate\Event\MigrateMapSaveEvent $event
+   *   The map event.
+   */
+  public static function onMapSave(MigrateMapSaveEvent $event) {
+    static::$numProcessed++;
+  }
+
+  /**
+   * Counts up any map delete events.
+   *
+   * @param \Drupal\migrate\Event\MigrateMapDeleteEvent $event
+   *   The map event.
+   */
+  public static function onMapDelete(MigrateMapDeleteEvent $event) {
+    static::$numProcessed++;
+  }
+
+  /**
+   * Displays any messages being logged to the ID map.
+   *
+   * @param \Drupal\migrate\Event\MigrateIdMapMessageEvent $event
+   *   The message event.
+   */
+  public static function onIdMapMessage(MigrateIdMapMessageEvent $event) {
+    if ($event->getLevel() == MigrationInterface::MESSAGE_NOTICE || $event->getLevel() == MigrationInterface::MESSAGE_INFORMATIONAL) {
+      $type = 'status';
+    }
+    else {
+      $type = 'error';
+    }
+    $source_id_string = implode(',', $event->getSourceIdValues());
+    $message = t('Source ID @source_id: @message', ['@source_id' => $source_id_string, '@message' => $event->getMessage()]);
+    static::$messages->display($message, $type);
+  }
+
+}
diff --git a/core/modules/migrate_drupal_ui/src/Batch/MigrateUpgradeImportBatch.php b/core/modules/migrate_drupal_ui/src/Batch/MigrateUpgradeImportBatch.php
new file mode 100644
index 0000000..045cdcd
--- /dev/null
+++ b/core/modules/migrate_drupal_ui/src/Batch/MigrateUpgradeImportBatch.php
@@ -0,0 +1,169 @@
+<?php
+
+namespace Drupal\migrate_drupal_ui\Batch;
+
+use Drupal\Core\StringTranslation\PluralTranslatableMarkup;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\migrate\Plugin\MigrationInterface;
+use Drupal\migrate\Event\MigrateEvents;
+use Drupal\migrate\MigrateExecutable;
+
+/**
+ * Runs a single migration batch.
+ */
+class MigrateUpgradeImportBatch extends MigrateUpgradeBatchBase {
+
+  /**
+   * Runs a single migrate import batch.
+   *
+   * @param int[] $initial_ids
+   *   The full set of migration IDs to import.
+   * @param array $config
+   *   An array of additional configuration from the form.
+   * @param array $context
+   *   The batch context.
+   *
+   */
+  public static function run($initial_ids, $config, &$context) {
+    if (!static::$listenersAdded) {
+      $event_dispatcher = \Drupal::service('event_dispatcher');
+      $event_dispatcher->addListener(MigrateEvents::POST_ROW_SAVE, [static::class, 'onPostRowSave']);
+      $event_dispatcher->addListener(MigrateEvents::MAP_SAVE, [static::class, 'onMapSave']);
+      $event_dispatcher->addListener(MigrateEvents::IDMAP_MESSAGE, [static::class, 'onIdMapMessage']);
+
+      static::$maxExecTime = ini_get('max_execution_time');
+      if (static::$maxExecTime <= 0) {
+        static::$maxExecTime = 60;
+      }
+      // Set an arbitrary threshold of 3 seconds (e.g., if max_execution_time is
+      // 45 seconds, we will quit at 42 seconds so a slow item or cleanup
+      // overhead don't put us over 45).
+      static::$maxExecTime -= 3;
+      static::$listenersAdded = TRUE;
+    }
+    if (!isset($context['sandbox']['migration_ids'])) {
+      $context['sandbox']['max'] = count($initial_ids);
+      $context['sandbox']['current'] = 1;
+      // Total number processed for this migration.
+      $context['sandbox']['num_processed'] = 0;
+      // migration_ids will be the list of IDs remaining to run.
+      $context['sandbox']['migration_ids'] = $initial_ids;
+      $context['sandbox']['messages'] = [];
+      $context['results']['failures'] = 0;
+      $context['results']['successes'] = 0;
+    }
+
+    // Number processed in this batch.
+    static::$numProcessed = 0;
+
+    $migration_id = reset($context['sandbox']['migration_ids']);
+    $definition = \Drupal::service('plugin.manager.migration')->getDefinition($migration_id);
+    $configuration = [];
+
+    // @todo Find a way to avoid this in https://www.drupal.org/node/2804611.
+    if ($definition['destination']['plugin'] === 'entity:file') {
+      // Make sure we have a single trailing slash.
+      $configuration['source']['constants']['source_base_path'] = rtrim($config['source_base_path'], '/') . '/';
+    }
+
+    /** @var \Drupal\migrate\Plugin\Migration $migration */
+    $migration = \Drupal::service('plugin.manager.migration')->createInstance($migration_id, $configuration);
+
+    if ($migration) {
+      static::$messages = new MigrateMessageCapture();
+      $executable = new MigrateExecutable($migration, static::$messages);
+
+      $migration_name = $migration->label() ? $migration->label() : $migration_id;
+
+      try {
+        $migration_status = $executable->import();
+      }
+      catch (\Exception $e) {
+        \Drupal::logger('migrate_drupal_ui')->error($e->getMessage());
+        $migration_status = MigrationInterface::RESULT_FAILED;
+      }
+
+      switch ($migration_status) {
+        case MigrationInterface::RESULT_COMPLETED:
+          // Store the number processed in the sandbox.
+          $context['sandbox']['num_processed'] += static::$numProcessed;
+          $message = new PluralTranslatableMarkup(
+            $context['sandbox']['num_processed'], 'Upgraded @migration (processed 1 item total)', 'Upgraded @migration (processed @count items total)',
+            ['@migration' => $migration_name]);
+          $context['sandbox']['messages'][] = (string) $message;
+          \Drupal::logger('migrate_drupal_ui')->notice($message);
+          $context['sandbox']['num_processed'] = 0;
+          $context['results']['successes']++;
+          break;
+
+        case MigrationInterface::RESULT_INCOMPLETE:
+          $context['sandbox']['messages'][] = (string) new PluralTranslatableMarkup(
+            static::$numProcessed, 'Continuing with @migration (processed 1 item)', 'Continuing with @migration (processed @count items)',
+            ['@migration' => $migration_name]);
+          $context['sandbox']['num_processed'] += static::$numProcessed;
+          break;
+
+        case MigrationInterface::RESULT_STOPPED:
+          $context['sandbox']['messages'][] = (string) new TranslatableMarkup('Operation stopped by request');
+          break;
+
+        case MigrationInterface::RESULT_FAILED:
+          $context['sandbox']['messages'][] = (string) new TranslatableMarkup('Operation on @migration failed', ['@migration' => $migration_name]);
+          $context['results']['failures']++;
+          \Drupal::logger('migrate_drupal_ui')->error('Operation on @migration failed', ['@migration' => $migration_name]);
+          break;
+
+        case MigrationInterface::RESULT_SKIPPED:
+          $context['sandbox']['messages'][] = (string) new TranslatableMarkup('Operation on @migration skipped due to unfulfilled dependencies', ['@migration' => $migration_name]);
+          \Drupal::logger('migrate_drupal_ui')->error('Operation on @migration skipped due to unfulfilled dependencies', ['@migration' => $migration_name]);
+          break;
+
+        case MigrationInterface::RESULT_DISABLED:
+          // Skip silently if disabled.
+          break;
+      }
+
+      // Unless we're continuing on with this migration, take it off the list.
+      if ($migration_status != MigrationInterface::RESULT_INCOMPLETE) {
+        array_shift($context['sandbox']['migration_ids']);
+        $context['sandbox']['current']++;
+      }
+
+      // Add and log any captured messages.
+      foreach (static::$messages->getMessages() as $message) {
+        $context['sandbox']['messages'][] = (string) $message;
+        \Drupal::logger('migrate_drupal_ui')->error($message);
+      }
+
+      // Only display the last MESSAGE_LENGTH messages, in reverse order.
+      $message_count = count($context['sandbox']['messages']);
+      $context['message'] = '';
+      for ($index = max(0, $message_count - self::MESSAGE_LENGTH); $index < $message_count; $index++) {
+        $context['message'] = $context['sandbox']['messages'][$index] . "<br />\n" . $context['message'];
+      }
+      if ($message_count > self::MESSAGE_LENGTH) {
+        // Indicate there are earlier messages not displayed.
+        $context['message'] .= '&hellip;';
+      }
+      // At the top of the list, display the next one (which will be the one
+      // that is running while this message is visible).
+      if (!empty($context['sandbox']['migration_ids'])) {
+        $migration_id = reset($context['sandbox']['migration_ids']);
+        $migration = \Drupal::service('plugin.manager.migration')->createInstance($migration_id);
+        $migration_name = $migration->label() ? $migration->label() : $migration_id;
+        $context['message'] = (string) new TranslatableMarkup('Currently upgrading @migration (@current of @max total tasks)', [
+            '@migration' => $migration_name,
+            '@current' => $context['sandbox']['current'],
+            '@max' => $context['sandbox']['max'],
+          ]) . "<br />\n" . $context['message'];
+      }
+    }
+    else {
+      array_shift($context['sandbox']['migration_ids']);
+      $context['sandbox']['current']++;
+    }
+
+    $context['finished'] = 1 - count($context['sandbox']['migration_ids']) / $context['sandbox']['max'];
+  }
+
+}
diff --git a/core/modules/migrate_drupal_ui/src/Batch/MigrateUpgradeImportFinish.php b/core/modules/migrate_drupal_ui/src/Batch/MigrateUpgradeImportFinish.php
new file mode 100644
index 0000000..dd226f2
--- /dev/null
+++ b/core/modules/migrate_drupal_ui/src/Batch/MigrateUpgradeImportFinish.php
@@ -0,0 +1,44 @@
+<?php
+
+namespace Drupal\migrate_drupal_ui\Batch;
+
+use Drupal\Core\Link;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\Core\Url;
+
+/**
+ * Finish the Migrate Upgrade Import batch process.
+ */
+class MigrateUpgradeImportFinish extends MigrateUpgradeBatchBase {
+
+  /**
+   * Callback executed when the Migrate Upgrade Import batch process completes.
+   */
+  public static function run($success, $results, $operations, $elapsed) {
+    $successes = $results['successes'];
+    $failures = $results['failures'];
+
+    // If we had any successes log that for the user.
+    if ($successes > 0) {
+      drupal_set_message(\Drupal::translation()
+        ->formatPlural($successes, 'Completed 1 upgrade task successfully', 'Completed @count upgrade tasks successfully'));
+    }
+    // If we had failures, log them and show the migration failed.
+    if ($failures > 0) {
+      drupal_set_message(\Drupal::translation()
+        ->formatPlural($failures, '1 upgrade failed', '@count upgrades failed'));
+      drupal_set_message(t('Upgrade process not completed'), 'error');
+    }
+    else {
+      // Everything went off without a hitch. We may not have had successes
+      // but we didn't have failures so this is fine.
+      drupal_set_message(t('Congratulations, you upgraded Drupal!'));
+    }
+
+    if (\Drupal::moduleHandler()->moduleExists('dblog')) {
+      $url = Url::fromRoute('migrate_drupal_ui.log');
+      drupal_set_message(Link::fromTextAndUrl(new TranslatableMarkup('Review the detailed upgrade log'), $url), $failures ? 'error' : 'status');
+    }
+  }
+
+}
diff --git a/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php b/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
index 2d60c46..077f606 100644
--- a/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
+++ b/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
@@ -9,7 +9,8 @@
 use Drupal\Core\State\StateInterface;
 use Drupal\Core\Url;
 use Drupal\migrate\Plugin\MigrationPluginManagerInterface;
-use Drupal\migrate_drupal_ui\MigrateUpgradeRunBatch;
+use Drupal\migrate_drupal_ui\Batch\MigrateUpgradeImportBatch;
+use Drupal\migrate_drupal_ui\Batch\MigrateUpgradeImportFinish;
 use Drupal\migrate_drupal\MigrationConfigurationTrait;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
@@ -1109,13 +1110,12 @@ public function submitConfirmForm(array &$form, FormStateInterface $form_state)
       'progress_message' => '',
       'operations' => [
         [
-          [MigrateUpgradeRunBatch::class, 'run'],
-          [array_keys($migrations), 'import', $config],
+          [MigrateUpgradeImportBatch::class, 'run'],
+          [array_keys($migrations), $config],
         ],
       ],
       'finished' => [
-        MigrateUpgradeRunBatch::class,
-        'finished',
+        MigrateUpgradeImportFinish::class, 'run',
       ],
     ];
     batch_set($batch);
diff --git a/core/modules/migrate_drupal_ui/src/MigrateUpgradeRunBatch.php b/core/modules/migrate_drupal_ui/src/MigrateUpgradeRunBatch.php
deleted file mode 100644
index 2a271fb..0000000
--- a/core/modules/migrate_drupal_ui/src/MigrateUpgradeRunBatch.php
+++ /dev/null
@@ -1,342 +0,0 @@
-<?php
-
-namespace Drupal\migrate_drupal_ui;
-
-use Drupal\Core\Link;
-use Drupal\Core\StringTranslation\PluralTranslatableMarkup;
-use Drupal\Core\StringTranslation\TranslatableMarkup;
-use Drupal\Core\Url;
-use Drupal\migrate\Plugin\MigrationInterface;
-use Drupal\migrate\Event\MigrateEvents;
-use Drupal\migrate\Event\MigrateIdMapMessageEvent;
-use Drupal\migrate\Event\MigrateMapDeleteEvent;
-use Drupal\migrate\Event\MigrateMapSaveEvent;
-use Drupal\migrate\Event\MigratePostRowSaveEvent;
-use Drupal\migrate\Event\MigrateRowDeleteEvent;
-use Drupal\migrate\MigrateExecutable;
-
-/**
- * Runs a single migration batch.
- */
-class MigrateUpgradeRunBatch {
-
-  /**
-   * Maximum number of previous messages to display.
-   */
-  const MESSAGE_LENGTH = 20;
-
-  /**
-   * The processed items for one batch of a given migration.
-   *
-   * @var int
-   */
-  protected static $numProcessed = 0;
-
-  /**
-   * Ensure we only add the listeners once per request.
-   *
-   * @var bool
-   */
-  protected static $listenersAdded = FALSE;
-
-  /**
-   * The maximum length in seconds to allow processing in a request.
-   *
-   * @see self::run()
-   *
-   * @var int
-   */
-  protected static $maxExecTime;
-
-  /**
-   * MigrateMessage instance to capture messages during the migration process.
-   *
-   * @var \Drupal\migrate_drupal_ui\MigrateMessageCapture
-   */
-  protected static $messages;
-
-  /**
-   * Runs a single migration batch.
-   *
-   * @param int[] $initial_ids
-   *   The full set of migration IDs to import.
-   * @param string $operation
-   *   The operation to perform. Only 'import' is currently supported.
-   * @param array $config
-   *   An array of additional configuration from the form.
-   * @param array $context
-   *   The batch context.
-   *
-   * @todo Remove the $operation parameter and conditionals for it below, and
-   *   refactor this method. https://www.drupal.org/node/2687851
-   */
-  public static function run($initial_ids, $operation, $config, &$context) {
-    if (!static::$listenersAdded) {
-      $event_dispatcher = \Drupal::service('event_dispatcher');
-      if ($operation == 'import') {
-        $event_dispatcher->addListener(MigrateEvents::POST_ROW_SAVE, [static::class, 'onPostRowSave']);
-        $event_dispatcher->addListener(MigrateEvents::MAP_SAVE, [static::class, 'onMapSave']);
-        $event_dispatcher->addListener(MigrateEvents::IDMAP_MESSAGE, [static::class, 'onIdMapMessage']);
-      }
-      static::$maxExecTime = ini_get('max_execution_time');
-      if (static::$maxExecTime <= 0) {
-        static::$maxExecTime = 60;
-      }
-      // Set an arbitrary threshold of 3 seconds (e.g., if max_execution_time is
-      // 45 seconds, we will quit at 42 seconds so a slow item or cleanup
-      // overhead don't put us over 45).
-      static::$maxExecTime -= 3;
-      static::$listenersAdded = TRUE;
-    }
-    if (!isset($context['sandbox']['migration_ids'])) {
-      $context['sandbox']['max'] = count($initial_ids);
-      $context['sandbox']['current'] = 1;
-      // Total number processed for this migration.
-      $context['sandbox']['num_processed'] = 0;
-      // migration_ids will be the list of IDs remaining to run.
-      $context['sandbox']['migration_ids'] = $initial_ids;
-      $context['sandbox']['messages'] = [];
-      $context['results']['failures'] = 0;
-      $context['results']['successes'] = 0;
-      $context['results']['operation'] = $operation;
-    }
-
-    // Number processed in this batch.
-    static::$numProcessed = 0;
-
-    $migration_id = reset($context['sandbox']['migration_ids']);
-    $definition = \Drupal::service('plugin.manager.migration')->getDefinition($migration_id);
-    $configuration = [];
-
-    // @todo Find a way to avoid this in https://www.drupal.org/node/2804611.
-    if ($definition['destination']['plugin'] === 'entity:file') {
-      // Make sure we have a single trailing slash.
-      $configuration['source']['constants']['source_base_path'] = rtrim($config['source_base_path'], '/') . '/';
-    }
-
-    /** @var \Drupal\migrate\Plugin\Migration $migration */
-    $migration = \Drupal::service('plugin.manager.migration')->createInstance($migration_id, $configuration);
-
-    if ($migration) {
-      static::$messages = new MigrateMessageCapture();
-      $executable = new MigrateExecutable($migration, static::$messages);
-
-      $migration_name = $migration->label() ? $migration->label() : $migration_id;
-
-      try {
-        if ($operation == 'import') {
-          $migration_status = $executable->import();
-        }
-      }
-      catch (\Exception $e) {
-        static::logger()->error($e->getMessage());
-        $migration_status = MigrationInterface::RESULT_FAILED;
-      }
-
-      switch ($migration_status) {
-        case MigrationInterface::RESULT_COMPLETED:
-          // Store the number processed in the sandbox.
-          $context['sandbox']['num_processed'] += static::$numProcessed;
-          if ($operation == 'import') {
-            $message = new PluralTranslatableMarkup(
-              $context['sandbox']['num_processed'], 'Upgraded @migration (processed 1 item total)', 'Upgraded @migration (processed @count items total)',
-              ['@migration' => $migration_name]);
-          }
-          $context['sandbox']['messages'][] = (string) $message;
-          static::logger()->notice($message);
-          $context['sandbox']['num_processed'] = 0;
-          $context['results']['successes']++;
-          break;
-
-        case MigrationInterface::RESULT_INCOMPLETE:
-          $context['sandbox']['messages'][] = (string) new PluralTranslatableMarkup(
-            static::$numProcessed, 'Continuing with @migration (processed 1 item)', 'Continuing with @migration (processed @count items)',
-            ['@migration' => $migration_name]);
-          $context['sandbox']['num_processed'] += static::$numProcessed;
-          break;
-
-        case MigrationInterface::RESULT_STOPPED:
-          $context['sandbox']['messages'][] = (string) new TranslatableMarkup('Operation stopped by request');
-          break;
-
-        case MigrationInterface::RESULT_FAILED:
-          $context['sandbox']['messages'][] = (string) new TranslatableMarkup('Operation on @migration failed', ['@migration' => $migration_name]);
-          $context['results']['failures']++;
-          static::logger()->error('Operation on @migration failed', ['@migration' => $migration_name]);
-          break;
-
-        case MigrationInterface::RESULT_SKIPPED:
-          $context['sandbox']['messages'][] = (string) new TranslatableMarkup('Operation on @migration skipped due to unfulfilled dependencies', ['@migration' => $migration_name]);
-          static::logger()->error('Operation on @migration skipped due to unfulfilled dependencies', ['@migration' => $migration_name]);
-          break;
-
-        case MigrationInterface::RESULT_DISABLED:
-          // Skip silently if disabled.
-          break;
-      }
-
-      // Unless we're continuing on with this migration, take it off the list.
-      if ($migration_status != MigrationInterface::RESULT_INCOMPLETE) {
-        array_shift($context['sandbox']['migration_ids']);
-        $context['sandbox']['current']++;
-      }
-
-      // Add and log any captured messages.
-      foreach (static::$messages->getMessages() as $message) {
-        $context['sandbox']['messages'][] = (string) $message;
-        static::logger()->error($message);
-      }
-
-      // Only display the last MESSAGE_LENGTH messages, in reverse order.
-      $message_count = count($context['sandbox']['messages']);
-      $context['message'] = '';
-      for ($index = max(0, $message_count - self::MESSAGE_LENGTH); $index < $message_count; $index++) {
-        $context['message'] = $context['sandbox']['messages'][$index] . "<br />\n" . $context['message'];
-      }
-      if ($message_count > self::MESSAGE_LENGTH) {
-        // Indicate there are earlier messages not displayed.
-        $context['message'] .= '&hellip;';
-      }
-      // At the top of the list, display the next one (which will be the one
-      // that is running while this message is visible).
-      if (!empty($context['sandbox']['migration_ids'])) {
-        $migration_id = reset($context['sandbox']['migration_ids']);
-        $migration = \Drupal::service('plugin.manager.migration')->createInstance($migration_id);
-        $migration_name = $migration->label() ? $migration->label() : $migration_id;
-        if ($operation == 'import') {
-          $context['message'] = (string) new TranslatableMarkup('Currently upgrading @migration (@current of @max total tasks)', [
-            '@migration' => $migration_name,
-            '@current' => $context['sandbox']['current'],
-            '@max' => $context['sandbox']['max'],
-          ]) . "<br />\n" . $context['message'];
-        }
-      }
-    }
-    else {
-      array_shift($context['sandbox']['migration_ids']);
-      $context['sandbox']['current']++;
-    }
-
-    $context['finished'] = 1 - count($context['sandbox']['migration_ids']) / $context['sandbox']['max'];
-  }
-
-  /**
-   * Returns the logger using the migrate_drupal_ui channel.
-   *
-   * @return \Psr\Log\LoggerInterface
-   *   The logger instance.
-   */
-  protected static function logger() {
-    return \Drupal::logger('migrate_drupal_ui');
-  }
-
-  /**
-   * Implements the Batch API finished method.
-   */
-  public static function finished($success, $results, $operations, $elapsed) {
-    static::displayResults($results);
-  }
-
-  /**
-   * Displays counts of success/failures on the migration upgrade complete page.
-   *
-   * @param array $results
-   *   An array of result data built during the batch.
-   */
-  protected static function displayResults($results) {
-    $successes = $results['successes'];
-    $failures = $results['failures'];
-
-    // If we had any successes log that for the user.
-    if ($successes > 0) {
-      if ($results['operation'] == 'import') {
-        drupal_set_message(new PluralTranslatableMarkup($successes, 'Completed 1 upgrade task successfully', 'Completed @count upgrade tasks successfully'));
-      }
-    }
-
-    // If we had failures, log them and show the migration failed.
-    if ($failures > 0) {
-      if ($results['operation'] == 'import') {
-        drupal_set_message(new PluralTranslatableMarkup($failures, '1 upgrade failed', '@count upgrades failed'));
-        drupal_set_message(new TranslatableMarkup('Upgrade process not completed'), 'error');
-      }
-    }
-    else {
-      if ($results['operation'] == 'import') {
-        // Everything went off without a hitch. We may not have had successes
-        // but we didn't have failures so this is fine.
-        drupal_set_message(new TranslatableMarkup('Congratulations, you upgraded Drupal!'));
-      }
-    }
-
-    if (\Drupal::moduleHandler()->moduleExists('dblog')) {
-      $url = Url::fromRoute('migrate_drupal_ui.log');
-      drupal_set_message(Link::fromTextAndUrl(new TranslatableMarkup('Review the detailed upgrade log'), $url), $failures ? 'error' : 'status');
-    }
-  }
-
-  /**
-   * Reacts to item import.
-   *
-   * @param \Drupal\migrate\Event\MigratePostRowSaveEvent $event
-   *   The post-save event.
-   */
-  public static function onPostRowSave(MigratePostRowSaveEvent $event) {
-    // We want to interrupt this batch and start a fresh one.
-    if ((time() - REQUEST_TIME) > static::$maxExecTime) {
-      $event->getMigration()->interruptMigration(MigrationInterface::RESULT_INCOMPLETE);
-    }
-  }
-
-  /**
-   * Reacts to item deletion.
-   *
-   * @param \Drupal\migrate\Event\MigrateRowDeleteEvent $event
-   *   The post-save event.
-   */
-  public static function onPostRowDelete(MigrateRowDeleteEvent $event) {
-    // We want to interrupt this batch and start a fresh one.
-    if ((time() - REQUEST_TIME) > static::$maxExecTime) {
-      $event->getMigration()->interruptMigration(MigrationInterface::RESULT_INCOMPLETE);
-    }
-  }
-
-  /**
-   * Counts up any map save events.
-   *
-   * @param \Drupal\migrate\Event\MigrateMapSaveEvent $event
-   *   The map event.
-   */
-  public static function onMapSave(MigrateMapSaveEvent $event) {
-    static::$numProcessed++;
-  }
-
-  /**
-   * Counts up any map delete events.
-   *
-   * @param \Drupal\migrate\Event\MigrateMapDeleteEvent $event
-   *   The map event.
-   */
-  public static function onMapDelete(MigrateMapDeleteEvent $event) {
-    static::$numProcessed++;
-  }
-
-  /**
-   * Displays any messages being logged to the ID map.
-   *
-   * @param \Drupal\migrate\Event\MigrateIdMapMessageEvent $event
-   *   The message event.
-   */
-  public static function onIdMapMessage(MigrateIdMapMessageEvent $event) {
-    if ($event->getLevel() == MigrationInterface::MESSAGE_NOTICE || $event->getLevel() == MigrationInterface::MESSAGE_INFORMATIONAL) {
-      $type = 'status';
-    }
-    else {
-      $type = 'error';
-    }
-    $source_id_string = implode(',', $event->getSourceIdValues());
-    $message = new TranslatableMarkup('Source ID @source_id: @message', ['@source_id' => $source_id_string, '@message' => $event->getMessage()]);
-    static::$messages->display($message, $type);
-  }
-
-}