Merged in feature/from-pantheon (pull request #16)

code from pantheon

* code from pantheon

wp/wp-content/plugins/wordpress-seo/src/actions/indexing/indexation-action-interface.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Yoast\WP\SEO\Actions\Indexing;
+
+/**
+ * Interface definition of reindexing action for indexables.
+ */
+interface Indexation_Action_Interface {
+
+	/**
+	 * Returns the total number of unindexed objects.
+	 *
+	 * @return int The total number of unindexed objects.
+	 */
+	public function get_total_unindexed();
+
+	/**
+	 * Indexes a number of objects.
+	 *
+	 * NOTE: ALWAYS use limits, this method is intended to be called multiple times over several requests.
+	 *
+	 * For indexing that requires JavaScript simply return the objects that should be indexed.
+	 *
+	 * @return array The reindexed objects.
+	 */
+	public function index();
+
+	/**
+	 * Returns the number of objects that will be indexed in a single indexing pass.
+	 *
+	 * @return int The limit.
+	 */
+	public function get_limit();
+}