fix(platform-browser): remove testing_e2e target (#10029)

The testing_e2e util does not belong in platform-browser and was never
intended to be a public API. Move it out of that whole tree.

BREAKING CHANGE:

The following API was never intended to be public and is removed:

```js
import {verifyNoBrowserErrors} from '@angular/platform-browser/testing_e2e';
```

Consider using Protractor's console plugin: https://github.com/angular/protractor-console-plugin

modules/e2e_util/perf_util.ts

@@ -0,0 +1,74 @@
+/**
+ * @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
+ */
+
+export {verifyNoBrowserErrors} from './e2e_util';
+
+var benchpress = (global as any /** TODO #9100 */)['benchpress'];
+var bind = benchpress.bind;
+var Options = benchpress.Options;
+
+export function runClickBenchmark(config: any /** TODO #9100 */) {
+  browser.ignoreSynchronization = !config.waitForAngular2;
+  var buttons =
+      config.buttons.map(function(selector: any /** TODO #9100 */) { return $(selector); });
+  config.work = function() {
+    buttons.forEach(function(button: any /** TODO #9100 */) { button.click(); });
+  };
+  return runBenchmark(config);
+}
+
+export function runBenchmark(config: any /** TODO #9100 */) {
+  return getScaleFactor(browser.params.benchmark.scaling).then(function(scaleFactor) {
+    var description = {};
+    var urlParams: any[] /** TODO #9100 */ = [];
+    if (config.params) {
+      config.params.forEach(function(param: any /** TODO #9100 */) {
+        var name = param.name;
+        var value = applyScaleFactor(param.value, scaleFactor, param.scale);
+        urlParams.push(name + '=' + value);
+        (description as any /** TODO #9100 */)[name] = value;
+      });
+    }
+    var url = encodeURI(config.url + '?' + urlParams.join('&'));
+    return browser.get(url).then(function() {
+      return (global as any /** TODO #9100 */)['benchpressRunner'].sample({
+        id: config.id,
+        execute: config.work,
+        prepare: config.prepare,
+        microMetrics: config.microMetrics,
+        providers: [{provide: Options.SAMPLE_DESCRIPTION, useValue: description}]
+      });
+    });
+  });
+}
+
+function getScaleFactor(possibleScalings: any /** TODO #9100 */) {
+  return browser.executeScript('return navigator.userAgent').then(function(userAgent: string) {
+    var scaleFactor = 1;
+    possibleScalings.forEach(function(entry: any /** TODO #9100 */) {
+      if (userAgent.match(entry.userAgent)) {
+        scaleFactor = entry.value;
+      }
+    });
+    return scaleFactor;
+  });
+}
+
+function applyScaleFactor(
+    value: any /** TODO #9100 */, scaleFactor: any /** TODO #9100 */,
+    method: any /** TODO #9100 */) {
+  if (method === 'log2') {
+    return value + Math.log(scaleFactor) / Math.LN2;
+  } else if (method === 'sqrt') {
+    return value * Math.sqrt(scaleFactor);
+  } else if (method === 'linear') {
+    return value * scaleFactor;
+  } else {
+    return value;
+  }
+}