cleanup(ui): clean up extra casts and functions

There is no need to create an extra callback to hide the overflow
menus, nor should we have to cast the elements if we give the array
the correct type in the first place.

Change-Id: I7a0f0b5a97564f6577c94aa095c7ed6c07a41cae

ui/controls.js

@@ -84,7 +84,7 @@ shaka.ui.Controls = class extends shaka.util.FakeEventTarget {
     /** @private {boolean} */
     this.isSeeking_ = false;
 
-    /** @private {!Array.<!Element>} */
+    /** @private {!Array.<!HTMLElement>} */
     this.settingsMenus_ = [];
 
     /**
@@ -132,13 +132,8 @@ shaka.ui.Controls = class extends shaka.util.FakeEventTarget {
      * @private {shaka.util.Timer}
      */
     this.hideSettingsMenusTimer_ = new shaka.util.Timer(() => {
-      /** @type {function(!HTMLElement)} */
-      const hide = (control) => {
-        shaka.ui.Utils.setDisplay(control, /* visible= */ false);
-      };
-
       for (const menu of this.settingsMenus_) {
-        hide(/** @type {!HTMLElement} */ (menu));
+        shaka.ui.Utils.setDisplay(menu, /* visible= */ false);
       }
     });