Convert recents.js to use async-await.

Bug: 909056
Change-Id: Ic44a7ba350b852fcdd0a2983125c7239dc8d7a1a
Reviewed-on: https://chromium-review.googlesource.com/c/1351328Reviewed-by: Luciano Pacheco <lucmult@chromium.org>
Commit-Queue: Sam McNally <sammc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612453}

ui/file_manager/integration_tests/file_manager/recents.js

 // Copyright 2018 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.
-
 'use strict';
 
-function generateVerifyRecentsSteps(expectedRecents = RECENT_ENTRY_SET) {
-  let appId;
-  return [
+async function verifyRecents(appId, expectedRecents = RECENT_ENTRY_SET) {
   // Navigate to Recents.
-    function(results) {
-      appId = results.windowId;
-      remoteCall.callRemoteTestUtil(
-          'fakeMouseClick', appId, ['span[root-type-icon=\'recent\']'],
-          this.next);
-    },
+  chrome.test.assertTrue(await remoteCall.callRemoteTestUtil(
+      'fakeMouseClick', appId, ['span[root-type-icon=\'recent\']']));
+
   // Verify Recents contains the expected files - those with an mtime in the
   // future.
-    function(result) {
-      chrome.test.assertTrue(result);
   const files = TestEntryInfo.getExpectedRows(expectedRecents);
-      remoteCall.waitForFiles(appId, files).then(this.next);
-    },
-    function() {
-      checkIfNoErrorsOccured(this.next);
-    }
-  ];
+  await remoteCall.waitForFiles(appId, files);
 }
 
-testcase.recentsDownloads = function() {
-  StepsRunner.run([
+testcase.recentsDownloads = async function() {
   // Populate downloads.
-    function() {
-      setupAndWaitUntilReady(
-          null, RootPath.DOWNLOADS, this.next, BASIC_LOCAL_ENTRY_SET, []);
-    },
-  ].concat(generateVerifyRecentsSteps()));
+  const {appId} = await setupAndWaitUntilReady(
+      null, RootPath.DOWNLOADS, null, BASIC_LOCAL_ENTRY_SET, []);
+  await verifyRecents(appId);
 };
 
-testcase.recentsDrive = function() {
-  StepsRunner.run([
+testcase.recentsDrive = async function() {
   // Populate drive.
-    function() {
-      setupAndWaitUntilReady(
-          null, RootPath.DRIVE, this.next, [], BASIC_DRIVE_ENTRY_SET);
-    },
-  ].concat(generateVerifyRecentsSteps()));
+  const {appId} = await setupAndWaitUntilReady(
+      null, RootPath.DRIVE, null, [], BASIC_DRIVE_ENTRY_SET);
+  await verifyRecents(appId);
 };
 
-testcase.recentsDownloadsAndDrive = function() {
-  StepsRunner.run([
+testcase.recentsDownloadsAndDrive = async function() {
   // Populate both downloads and drive with disjoint sets of files.
-    function() {
-      setupAndWaitUntilReady(
-          null, RootPath.DOWNLOADS, this.next,
+  const {appId} = await setupAndWaitUntilReady(
+      null, RootPath.DOWNLOADS, null,
       [ENTRIES.beautiful, ENTRIES.hello, ENTRIES.photos],
       [ENTRIES.desktop, ENTRIES.world, ENTRIES.testDocument]);
-    },
-  ].concat(generateVerifyRecentsSteps()));
+  await verifyRecents(appId);
 };
 
-testcase.recentsDownloadsAndDriveWithOverlap = function() {
-  StepsRunner.run([
+testcase.recentsDownloadsAndDriveWithOverlap = async function() {
   // Populate both downloads and drive with overlapping sets of files.
-    function() {
-      setupAndWaitUntilReady(null, RootPath.DOWNLOADS, this.next);
-    },
-  ].concat(generateVerifyRecentsSteps(RECENT_ENTRY_SET
-                                          .concat(RECENT_ENTRY_SET))));
+  const {appId} = await setupAndWaitUntilReady(null, RootPath.DOWNLOADS, null);
+  await verifyRecents(appId, RECENT_ENTRY_SET.concat(RECENT_ENTRY_SET));
 };