Wait until Files app is fully loaded

Change setupAndWaitUntilReady function to wait until Files app is fully
loaded. This intend to fix flaky tests where tests expect to have Files
app loaded in Downloads folder, however EntryList |updateSubDirectories|
method is being refactored to be asynchronous, which makes Downloads
folder to delay its appearance. This change has had 4 successful runs in
a row in crrev.com/c/1312185 (patchset 2 and 3).

Re-enable test that was flaky on MSAN.

Bug: 899664
Change-Id: Iedff85699c56f6cf8ac82d5ea27ef0ca54b7a641
Reviewed-on: https://chromium-review.googlesource.com/c/1313709Reviewed-by: Joel Hockey <joelhockey@chromium.org>
Commit-Queue: Luciano Pacheco <lucmult@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604740}

chrome/browser/chromeos/file_manager/file_manager_browsertest.cc

@@ -278,10 +278,7 @@ WRAPPED_INSTANTIATE_TEST_CASE_P(
     FilesAppBrowserTest,
     ::testing::Values(TestCase("selectCreateFolderDownloads").InGuestMode(),
                       TestCase("selectCreateFolderDownloads"),
-// This test is flaky in MSAN, disabling until is fixed: crbug.com/899664.
-#if !defined(MEMORY_SANITIZER)
                       TestCase("createFolderDownloads").InGuestMode(),
-#endif
                       TestCase("createFolderDownloads"),
                       TestCase("createFolderNestedDownloads"),
                       TestCase("createFolderDrive").DisableDriveFs(),

ui/file_manager/file_manager/foreground/js/directory_model.js

@@ -972,6 +972,9 @@ DirectoryModel.prototype.changeDirectoryEntry = function(
   if (dirEntry instanceof VolumeEntry)
     dirEntry = assert(dirEntry.rootEntry);
 
+  // TODO(lucmult): Remove this log once flakiness is fixed.
+  console.log('changeDirectoryEntry: ' + dirEntry.name);
+
   // Increment the sequence value.
   this.changeDirectorySequence_++;
   this.clearSearch_();

ui/file_manager/integration_tests/file_manager/background.js

@@ -372,13 +372,16 @@ function setupAndWaitUntilReady(
   if (opt_callback)
     opt_callback = chrome.test.callbackPass(opt_callback);
 
+  let result;
   return Promise.all([
     windowPromise,
     localEntriesPromise,
     driveEntriesPromise,
     detailedTablePromise
   ]).then(function(results) {
-    var result = {windowId: results[0], fileList: results[3]};
+    result = {windowId: results[0], fileList: results[3]};
+    return remoteCall.waitFor('isFileManagerLoaded', result.windowId, true);
+  }).then(() => {
     if (opt_callback)
       opt_callback(result);
     return result;