Move downloads.FocusRow.shouldFocus to cr.ui.FocusRow.isFocusable

ui/webui/resources/js/cr/ui/focus_row.js

Index: ui/webui/resources/js/cr/ui/focus_row.js
diff --git a/ui/webui/resources/js/cr/ui/focus_row.js b/ui/webui/resources/js/cr/ui/focus_row.js
index 3006d640075dee45c262a6c94f09b3c836039c2c..1065c0aa3e88a955c957eb7114ba418271b5457f 100644
--- a/ui/webui/resources/js/cr/ui/focus_row.js
+++ b/ui/webui/resources/js/cr/ui/focus_row.js
@@ -57,6 +57,24 @@ cr.define('cr.ui', function() {
   /** @const {string} */
   FocusRow.ACTIVE_CLASS = 'focus-row-active';
 
+  /**
+   * Whether it's possible that |element| can be focused.
+   * @param {Element} element
+   * @return {boolean} Whether the item is focusable.
+   */
+  FocusRow.isFocusable = function isFocusable(element) {
+    if (!element)
+      return false;
+
+    // Hidden elements are not focusable.
+    var style = window.getComputedStyle(element);
+    if (style.visibility == 'hidden' || style.display == 'none')
+      return false;
+
+    // Verify all ancestors are focusable.
+    return !element.parentElement || isFocusable(element.parentElement);
+  };
+
   FocusRow.prototype = {
     __proto__: HTMLDivElement.prototype,