md-settings: Fix back navigation from /resetProfileSettings.

chrome/test/data/webui/test_util.js

Index: chrome/test/data/webui/test_util.js
diff --git a/chrome/test/data/webui/test_util.js b/chrome/test/data/webui/test_util.js
new file mode 100644
index 0000000000000000000000000000000000000000..4457182733e145ef51a60f0fa3574053ad2e1921
--- /dev/null
+++ b/chrome/test/data/webui/test_util.js
@@ -0,0 +1,16 @@
+// 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.
+
+/*
+ * Waits for queued up tasks to finish before proceeding. Inspired by:
+ * https://github.com/Polymer/web-component-tester/blob/master/browser/environment/helpers.js#L97
+ */
+function flush() {

[michaelpg, 2016/10/04 05:40:49]

please don't call this "flush" -- the more recognizable Polymer.dom.flush does
something fundamentally very different.

also: if this Promise is resolved on the next [macro]task, isn't it redundant to
call Polymer.dom.flush (assuming users wait for the returned promise to
resolve)?

[alito, 2016/10/04 21:22:59]

I renamed this to flushTasks() which sound quite explicit to me. Feel free to
suggest alternatives.

Also removed the call to Polymer.dom.flush().

[michaelpg, 2016/10/04 22:12:15]

great, thanks!
Hmm, maybe my suggestion is causing the History failures then? There might be
timing issues somewhere that could depend on the original ordering for some
reason -- see if adding this back fixes it?

+  Polymer.dom.flush();

[michaelpg, 2016/10/04 05:40:49]

Use a more specific filename, or maybe just add to polymer_browser_test_base.js
(perhaps as a method). It's weird for a file named "test_util.js" to depend on
Polymer, as this does.

[alito, 2016/10/04 21:22:59]

Moved the function to polymer_browser_test_base.js.

+  // Promises have microtask timing, so we use setTimeout to explicity force a
+  // new task.
+  return new Promise(function(resolve, reject) {
+    window.setTimeout(resolve, 0);
+  });
+}