fix(build): test example directories with unit and e2e tests (#11296)

modules/@angular/examples/_common/e2e_util.ts

@@ -0,0 +1,25 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+import * as webdriver from 'selenium-webdriver';
+declare var browser: any;
+declare var expect: any;
+
+// TODO (juliemr): remove this method once this becomes a protractor plugin
+export function verifyNoBrowserErrors() {
+  browser.manage().logs().get('browser').then(function(browserLog) {
+    var errors: any[] = [];
+    browserLog.filter(logEntry => {
+      var msg = logEntry.message;
+      console.log('>> ' + msg);
+      if (logEntry.level.value >= webdriver.logging.Level.INFO.value) {
+        errors.push(msg);
+      }
+    });
+    expect(errors).toEqual([]);
+  });
+}