MD WebUI: Make cr-lazy-render get() synchronous

chrome/browser/resources/md_history/synced_device_manager.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @typedef {{device: string,
  *           lastUpdateTime: string,
  *           opened: boolean,
  *           separatorIndexes: !Array<number>,
  *           timestamp: number,
@@ skipping 116 matching lines @@
     chrome.send('startSignInFlow');
   },
 
   onListScroll_: function() {
     var menu = this.$.menu.getIfExists();
     if (menu)
       menu.closeMenu();
   },
 
   onToggleMenu_: function(e) {
-    this.$.menu.get().then(function(menu) {
-      menu.toggleMenu(e.detail.target, e.detail.tag);
-      if (menu.menuOpen) {
-        md_history.BrowserService.getInstance().recordHistogram(
-            SYNCED_TABS_HISTOGRAM_NAME, SyncedTabsHistogram.SHOW_SESSION_MENU,
-            SyncedTabsHistogram.LIMIT);
-      }
-    });
+    var menu = /** @type {CrSharedMenuElement} */ this.$.menu.get();
+    menu.toggleMenu(e.detail.target, e.detail.tag);
+    if (menu.menuOpen) {
+      md_history.BrowserService.getInstance().recordHistogram(
+          SYNCED_TABS_HISTOGRAM_NAME, SyncedTabsHistogram.SHOW_SESSION_MENU,
+          SyncedTabsHistogram.LIMIT);
+    }
   },
 
   onOpenAllTap_: function() {
     var menu = assert(this.$.menu.getIfExists());
     var browserService = md_history.BrowserService.getInstance();
     browserService.recordHistogram(
         SYNCED_TABS_HISTOGRAM_NAME, SyncedTabsHistogram.OPEN_ALL,
         SyncedTabsHistogram.LIMIT);
     browserService.openForeignSessionAllTabs(
         menu.itemData);
@@ skipping 127 matching lines @@
     // User signed in, show the loading message when querying for synced
     // devices.
     this.fetchingSyncedTabs_ = true;
   },
 
   searchTermChanged: function(searchTerm) {
     this.clearDisplayedSyncedDevices_();
     this.updateSyncedDevices(this.sessionList);
   }
 });