MD Bookmarks: Lazily render dropdown menus

chrome/browser/resources/md_bookmarks/toolbar.js

Index: chrome/browser/resources/md_bookmarks/toolbar.js
diff --git a/chrome/browser/resources/md_bookmarks/toolbar.js b/chrome/browser/resources/md_bookmarks/toolbar.js
index 152eadfba702c57e0f46fbb158689a2f05ef8189..6a2d98ea5fdde23e1083f595dcf8ee1704e9e925 100644
--- a/chrome/browser/resources/md_bookmarks/toolbar.js
+++ b/chrome/browser/resources/md_bookmarks/toolbar.js
@@ -78,7 +78,7 @@ Polymer({
    * @private
    */
   onMenuButtonOpenTap_: function(e) {
-    var menu = /** @type {!CrActionMenuElement} */ (this.$.dropdown);
+    var menu = /** @type {!CrActionMenuElement} */ (this.$.dropdown.get());

[calamity, 2017/06/21 08:38:27]

Why does this not require an immediate flush?

[tsergeant, 2017/06/22 00:10:12]

The flush() is only needed to work with the dom-repeat, forcing the dom-repeat
to render its elements before the menu is positioned and shown.

Since this menu doesn't have a dom-repeat, all of its menu items will be
synchronously rendered during get().

     menu.showAt(/** @type {!Element} */ (e.target));
   },
 
@@ -134,7 +134,7 @@ Polymer({
 
   /** @private */
   closeDropdownMenu_: function() {
-    var menu = /** @type {!CrActionMenuElement} */ (this.$.dropdown);
+    var menu = /** @type {!CrActionMenuElement} */ (this.$.dropdown.get());
     menu.close();
   },