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

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

Index: chrome/test/data/webui/md_history/md_history_browsertest.js
diff --git a/chrome/test/data/webui/md_history/md_history_browsertest.js b/chrome/test/data/webui/md_history/md_history_browsertest.js
index 50bac182272fe44377d5a624224c130a184d4d43..be91cf4e4172430f5f617f3a5dd15ba26533613f 100644
--- a/chrome/test/data/webui/md_history/md_history_browsertest.js
+++ b/chrome/test/data/webui/md_history/md_history_browsertest.js
@@ -33,6 +33,7 @@ MaterialHistoryBrowserTest.prototype = {
     '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',
@@ -79,6 +80,11 @@ TEST_F('MaterialHistoryBrowserTest', 'HistoryListTest', function() {
   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();