MD History: Add confirmation dialog when deleting items from the toolbar

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

Index: chrome/test/data/webui/md_history/history_list_test.js
diff --git a/chrome/test/data/webui/md_history/history_list_test.js b/chrome/test/data/webui/md_history/history_list_test.js
index d43bde1fff544f859f653b7e66cdf9b3c0a48f5f..0ccad6a453a07b595909a15ac7015bf958680251 100644
--- a/chrome/test/data/webui/md_history/history_list_test.js
+++ b/chrome/test/data/webui/md_history/history_list_test.js
@@ -196,6 +196,7 @@ cr.define('md_history.history_list_test', function() {
       });
 
       test('delete items end to end', function(done) {
+        var listContainer = app.$.history;
         app.historyResult(createHistoryInfo(), TEST_HISTORY_RESULTS);
         app.historyResult(createHistoryInfo(), ADDITIONAL_RESULTS);
         flush().then(function() {
@@ -216,11 +217,17 @@ cr.define('md_history.history_list_test', function() {
                            '2016-03-13');
               assertEquals(element.historyData_[4].dateRelativeDay,
                            '2016-03-11');
+              assertFalse(listContainer.$.dialog.opened);
               done();
             });
           });
 
           MockInteractions.tap(app.$.toolbar.$$('#delete-button'));
+
+          // Confirmation dialog should appear.
+          assertTrue(listContainer.$.dialog.opened);
+
+          MockInteractions.tap(listContainer.$$('.action-button'));
         });
       });