Compiling file_manager, part 2: remove all warnings not caused by Object.freeze()-like enums

ui/file_manager/file_manager/foreground/js/thumbnail_loader.js

Index: ui/file_manager/file_manager/foreground/js/thumbnail_loader.js
diff --git a/ui/file_manager/file_manager/foreground/js/thumbnail_loader.js b/ui/file_manager/file_manager/foreground/js/thumbnail_loader.js
index 1c43123eee682a04d34688af1e5a6bd158e12015..28a15bd105a67d8abd4a5a9b0c1011eb4318d08f 100644
--- a/ui/file_manager/file_manager/foreground/js/thumbnail_loader.js
+++ b/ui/file_manager/file_manager/foreground/js/thumbnail_loader.js
@@ -142,8 +142,8 @@ ThumbnailLoader.THUMBNAIL_MAX_HEIGHT = 500;
  *     for downloading thumbnails. By default optimizations are disabled.
  * @param {function(Image, Object)=} opt_onSuccess Success callback,
  *     accepts the image and the transform.
- * @param {function=} opt_onError Error callback.
- * @param {function=} opt_onGeneric Callback for generic image used.
+ * @param {function()=} opt_onError Error callback.
+ * @param {function()=} opt_onGeneric Callback for generic image used.
  */
 ThumbnailLoader.prototype.load = function(box, fillMode, opt_optimizationMode,
     opt_onSuccess, opt_onError, opt_onGeneric) {