refactor(benchamrks_external): Ts'ify benchmarks_external

Translates benchmarks_external to TypeScript.

modules/benchmarks_external/e2e_test/tree_perf.ts

@@ -0,0 +1,18 @@
+import {runClickBenchmark, verifyNoBrowserErrors} from 'angular2/src/test_lib/perf_util';
+
+describe('ng1.x tree benchmark', function() {
+
+  var URL = 'benchmarks_external/src/tree/tree_benchmark.html';
+
+  afterEach(verifyNoBrowserErrors);
+
+  it('should log the stats', function(done) {
+    runClickBenchmark({
+      url: URL,
+      buttons: ['#destroyDom', '#createDom'],
+      id: 'ng1.tree',
+      params: [{name: 'depth', value: 9, scale: 'log2'}]
+    }).then(done, done.fail);
+  });
+
+});