Revert of All changes to ui/webui/ from bookmarks CL that block other CLs

ui/webui/resources/js/cr/ui/context_menu_button.js

Index: ui/webui/resources/js/cr/ui/context_menu_button.js
diff --git a/ui/webui/resources/js/cr/ui/context_menu_button.js b/ui/webui/resources/js/cr/ui/context_menu_button.js
index 51d1b52f57fb36ab2be96c435bc847b5afc23ebe..7d324e3ce0fde81f7e45aac4e434ca55edb84bbf 100644
--- a/ui/webui/resources/js/cr/ui/context_menu_button.js
+++ b/ui/webui/resources/js/cr/ui/context_menu_button.js
@@ -13,15 +13,14 @@
   /**
    * Helper function for ContextMenuButton to find the first ancestor of the
    * button that has a context menu.
-   * @param {!cr.ui.MenuButton} button The button to start the search from.
+   * @param {!MenuButton} el The button to start the search from.
    * @return {HTMLElement} The found element or null if not found.
    */
-  function getContextMenuTarget(button) {
-    var el = button;
+  function getContextMenuTarget(el) {
     do {
       el = el.parentNode;
     } while (el && !('contextMenu' in el));
-    return el ? assertInstanceof(el, HTMLElement) : null;
+    return el;
   }
 
   /**
@@ -29,7 +28,7 @@
    * ancestor that has a {@code contextMenu} property.
    * @param {Object=} opt_propertyBag Optional properties.
    * @constructor
-   * @extends {cr.ui.MenuButton}
+   * @extends {MenuButton}
    */
   var ContextMenuButton = cr.ui.define('button');
 
@@ -81,7 +80,7 @@
       var self = this;
       window.setTimeout(function() {
         MenuButton.prototype.showMenu.call(self, shouldSetFocus);
-      }, 0);
+      });
     }
   };