[MD History] Add UMA stats for switching views and the CBD button.

chrome/test/data/webui/md_history/md_history_browsertest.js

 // Copyright 2015 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.
 
 /**
  * @fileoverview Test suite for the Material Design history page.
  */
 
 var ROOT_PATH = '../../../../../';
 
@@ skipping 15 matching lines @@
   /** @override */
   runAccessibilityChecks: false,
 
   extraLibraries: PolymerTest.getLibraries(ROOT_PATH).concat([
     'test_util.js',
     'browser_service_test.js',
     'history_drawer_test.js',
     'history_grouped_list_test.js',
     'history_item_test.js',
     'history_list_test.js',
+    'history_metrics_test.js',
     'history_overflow_menu_test.js',
     'history_routing_test.js',
     'history_supervised_user_test.js',
     'history_synced_tabs_test.js',
     'history_toolbar_test.js',
     'lazy_render_test.js'
   ]),
 
   /** @override */
   setUp: function() {
@@ skipping 26 matching lines @@
 TEST_F('MaterialHistoryBrowserTest', 'HistoryItemTest', function() {
   md_history.history_item_test.registerTests();
   mocha.run();
 });
 
 TEST_F('MaterialHistoryBrowserTest', 'HistoryListTest', function() {
   md_history.history_list_test.registerTests();
   mocha.run();
 });
 
+TEST_F('MaterialHistoryBrowserTest', 'HistoryMetricsTest', function() {

[tsergeant, 2016/08/17 06:03:10]

Nit: For new tests, I've been leaving out the History prefix

MaterialHistoryBrowserTest.MetricsTest

(we could probably go one step further and get rid of the Test suffix as well)

[calamity, 2016/08/18 03:11:15]

Done.

+  md_history.history_metrics_test.registerTests();
+  mocha.run();
+});
+
 TEST_F('MaterialHistoryBrowserTest', 'HistoryToolbarTest', function() {
   md_history.history_toolbar_test.registerTests();
   mocha.run();
 });
 
 TEST_F('MaterialHistoryBrowserTest', 'HistoryToolbarFocusTest', function() {
   md_history.history_toolbar_focus_test.registerTests();
   mocha.run();
 });
 
@@ skipping 60 matching lines @@
       return waitForAppUpgrade();
     });
   },
 };
 
 TEST_F('MaterialHistoryWithQueryParamTest', 'RoutingTestWithQueryParam',
   function() {
     md_history.history_routing_test_with_query_param.registerTests();
     mocha.run();
 });