Created a test page for window.history.[push/replace]State() tests.

ios/testing/data/http_server_files/state_operations.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.
+
+// Populates onload text and clear no-op text.
+window.onload = function() {
+  updateOnLoadText('OnLoadText');
+  updateNoOpText('');
+};
+
+var updateOnLoadText = function(text) {
+  document.getElementById('on-load').innerHTML = text;
+}
+
+var updateNoOpText = function(text) {
+  document.getElementById('no-op').innerHTML = text;
+}
+
+var isOnLoadTextVisible = function() {

[Eugene But (OOO till 7-30), 2017/01/20 21:55:04]

This name makes me think that result is true if text of on-load is visible. Not
when it is default. Could you please rename it?

[kkhorimoto, 2017/01/21 01:38:24]

Changed to isOnLoadPlaceholderTextVisible.

+  return document.getElementById('on-load').innerHTML == 'OnLoadText';
+}
+
+var isNoOpTextVisible = function() {

[Eugene But (OOO till 7-30), 2017/01/20 21:55:04]

ditto

[kkhorimoto, 2017/01/21 01:38:24]

Done.

+  return document.getElementById('no-op').innerHTML == 'NoOpText';
+}
+
+// When a button is tapped, a 0,5s timeout begins that will call this function.
+var onNoOpTimeout = function() {
+  document.getElementById('no-op').innerHTML = 'NoOpText';
+}
+
+// Updates |gStateParams| to hold the specified values.  These are later used as
+// input parameters to history state changes.
+var gStateParams = {};
+var updateStateParams = function(obj, title, url) {
+  gStateParams.obj = obj;
+  gStateParams.title = title;
+  gStateParams.url = url;
+}
+
+// Returns whether the input parameters are reflected in |gStateParams|.
+var checkStateParams = function(obj, title, url) {
+  return gStateParams.obj == obj &&
+    gStateParams.title == title &&
+    gStateParams.url == url;
+}
+
+// Clears div text so tests can verify that the reported values are the result
+// of the latest executed script.
+var onButtonTapped = function() {
+  updateOnLoadText('');
+  updateNoOpText('');
+  setTimeout(onNoOpTimeout, 500);
+}
+
+var pushStateAction = function() {
+  onButtonTapped();
+  window.history.pushState(gStateParams.obj, gStateParams.title,
+                           gStateParams.url);
+}
+
+var replaceStateAction = function() {
+  onButtonTapped();
+  window.history.replaceState(gStateParams.obj, gStateParams.title,
+                              gStateParams.url);
+}
+