Fix "Set pages" drop crash by changing outside drags to simply add a new URL

chrome/browser/ui/webui/options/startup_page_list_browsertest.js

Index: chrome/browser/ui/webui/options/startup_page_list_browsertest.js
diff --git a/chrome/browser/ui/webui/options/startup_page_list_browsertest.js b/chrome/browser/ui/webui/options/startup_page_list_browsertest.js
new file mode 100644
index 0000000000000000000000000000000000000000..0cf7b7c0798af1c79d6a4b6da49eb1b25f64c4ef
--- /dev/null
+++ b/chrome/browser/ui/webui/options/startup_page_list_browsertest.js
@@ -0,0 +1,148 @@
+// Copyright 2013 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.
+
+/**
+ * Fixture for startup pages WebUI tests.
+ * @extends {testing.Test}
+ * @constructor
+ */
+function StartupPageListWebUITest() {}
+
+StartupPageListWebUITest.prototype = {
+  __proto__: testing.Test.prototype,
+
+  /**
+   * Browse to the options page & call our preLoad().
+   * @override
+   */
+  browsePreload: 'chrome://settings-frame/startup',
+
+  /** @override */
+  setUp: function() {
+    StartupOverlay.updateStartupPages(this.fakeStartupList);
+    // 1 item for entering data, 1+ from |this.fakeStartupList|.
+    assertGE(this.getList().items.length, 2);
+  },
+
+  /**
+   * Returns the list to be tested.
+   * @return {Element}
+   * @protected
+   */
+  getList: function() {
+    return $('startupPagesList');
+  },
+
+  /**
+   * Register a mock handler to ensure expectations are met and options pages
+   * behave correctly.
+   * @override
+   */
+  preLoad: function() {
+    this.makeAndRegisterMockHandler(['addStartupPage',
+                                     'dragDropStartupPage']);
+  },
+
+  /**
+   * A fake list of startup pages to send to the overlay.
+   * @protected
+   */
+  fakeStartupList: [
+    {
+      title: 'Yahoo!',
+      url: 'http://yahoo.com',
+      tooltip: 'Yahoo! homepage',
+      modelIndex: 0
+    },
+    {
+      title: 'Facebook',
+      url: 'http://facebook.com',
+      tooltip: 'Facebook :: Sign In',
+      modelIndex: 1
+    }
+  ],
+};
+
+(function() {
+
+/**
+ * A mock data transfer object for drag/drop events.
+ * @constructor
+ */
+function MockDataTransfer() {
+  /**
+   * The data this dataTransfer object knows about.
+   * @type {!Object.<string, string>}
+   * @private
+   */
+  this.data_ = {};
+}
+
+/**
+ * Installs a lazily created MockDataTransfer on event#dataTransfer.
+ * @param {!Event} event An event to modify.
+ */
+MockDataTransfer.install = function(event) {
+  event.__defineGetter__('dataTransfer', function() {
+    event.dataTransfer_ = event.dataTransfer_ || new MockDataTransfer;
+    return event.dataTransfer_;
+  });
+};
+
+MockDataTransfer.prototype = {
+  /**
+   * The URL data in this mock drop event.
+   * @param {string} type The text of data being set.
+   * @param {*} val The data to set. Will be stringified.
+   */
+  setData: function(type, val) {
+    this.data_[type] = String(val);
+  },
+
+  /**
+   * Gets data associated with this fake data transfer.
+   * @param {string} type The type of data to get.
+   * @returns {string} The requested type of data or '' if not set.
+   */
+  getData: function(type) {
+    return this.data_[type] || '';
+  },
+};
+
+/**
+ * Creates a fake bubbling, cancelable mouse event with a mock data transfer
+ * installed.
+ * @param {string} type A type of mouse event (e.g. 'drop').
+ * @return {!Event} A fake mouse event.
+ */
+function createMouseEvent(type) {
+  var event = new MouseEvent(type, {bubbles: true, cancelable: true});
+  MockDataTransfer.install(event);
+  return event;
+}
+
+TEST_F('StartupPageListWebUITest', 'testDropFromOutsideSource', function() {
+  /** @const */ var NEW_PAGE = 'http://google.com';
+
+  var mockDropEvent = createMouseEvent('drop');
+  mockDropEvent.dataTransfer.setData('url', NEW_PAGE);
+
+  this.mockHandler.expects(once()).addStartupPage([NEW_PAGE, 0]);
+
+  this.getList().items[0].dispatchEvent(mockDropEvent);
+
+  expectTrue(mockDropEvent.defaultPrevented);
+});
+
+TEST_F('StartupPageListWebUITest', 'testDropToReorder', function() {
+  // TODO(dbeam): mock4js doesn't handle complex arguments well. Fix this.
+  this.mockHandler.expects(once()).dragDropStartupPage([0, [1].join()]);
+
+  this.getList().selectionModel.selectedIndex = 1;
+  expectEquals(1, this.getList().selectionModel.selectedIndexes.length);
+
+  this.getList().items[0].dispatchEvent(createMouseEvent('drop'));
+});
+
+}());