[VideoPlayer] Browser tests for new separated video player app

chrome/browser/resources/video_player/js/error_util.js

+// Copyright 2014 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';
+
+/**
+ * This variable is checked in SelectFileDialogExtensionBrowserTest.
+ * @type {number}
+ */
+window.JSErrorCount = 0;
+
+/**
+ * Counts uncaught exceptions.
+ */
+window.onerror = function() { window.JSErrorCount++; };
+
+/**
+ * Wraps the function to use it as a callback.
+ * This does:
+ *  - Capture the stack trace in case of error.
+ *  - Bind this object
+ *
+ * @param {Object} thisObject Object to be used as this.
+ * @return {function} Wapped function.
+ */
+Function.prototype.wrap = function(thisObject) {
+  var func = this;
+  var liveStack = (new Error('Stack trace before async call')).stack;
+  if (thisObject === undefined)
+    thisObject = null;
+
+  return function wrappedCallback() {
+    try {
+      return func.apply(thisObject, arguments);
+    } catch (e) {
+      console.error('Exception happens in callback.', liveStack);
+
+      window.JSErrorCount++;
+      throw e;
+    }
+  }
+};