Nit @struct isn't needed for ES6 classes

Change-Id: Ib5f588376e29dcde496c941d670369afa49fe849
Reviewed-on: https://chromium-review.googlesource.com/c/1459859Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Reviewed-by: Noel Gordon <noel@chromium.org>
Commit-Queue: Luciano Pacheco <lucmult@chromium.org>
Commit-Queue: Noel Gordon <noel@chromium.org>
Auto-Submit: Luciano Pacheco <lucmult@chromium.org>
Cr-Commit-Position: refs/heads/master@{#630153}

ui/file_manager/file_manager/foreground/js/file_selection.js

@@ -139,7 +139,6 @@ class FileSelectionHandler extends cr.EventTarget {
    * @param {!MetadataModel} metadataModel
    * @param {!VolumeManager} volumeManager
    * @param {!AllowedPaths} allowedPaths
-   * @struct
    */
   constructor(
       directoryModel, fileOperationManager, listContainer, metadataModel,