Index: src/wp-admin/includes/revision.php
===================================================================
--- src/wp-admin/includes/revision.php	(revision 30994)
+++ src/wp-admin/includes/revision.php	(working copy)
@@ -199,7 +199,7 @@
 			$current_id = $revision->ID;
 		}
 
-		$revisions[ $revision->ID ] = array(
+		$revisions_data = array(
 			'id'         => $revision->ID,
 			'title'      => get_the_title( $post->ID ),
 			'author'     => $authors[ $revision->post_author ],
@@ -210,6 +210,18 @@
 			'current'    => $current,
 			'restoreUrl' => $can_restore ? $restore_link : false,
 		);
+
+		/**
+		 * Filter the array of models used to load the revisions screen.
+		 *
+		 * @since 4.2.0
+		 *
+		 * @param array   $revisions_data The bootstrapped data for the revisions
+		 *                                screen Backbone Collection.
+		 * @param WP_Post $post           The revisions parent post object.
+		 */
+		$revisions[ $revision->ID ] = apply_filters( 'wp_prepare_revision_for_js', $revisions_data, $post );
+
 	}
 
 	/**