WebUI: Add cr-dialog tests to ensure 'close' and 'cancel' events are …

…bubbling.

This is in preparation for migrating to Polymer2, which uses Shadow DOM v1,
which changed the bubbling behavior of various events to not bubble. These
tests will fail in v1, without additional changes to cr-dialog itself.

Bug: 848518
Change-Id: I5eb7c7c1c1c5eae325649d50952299f4d84337ef
Reviewed-on: https://chromium-review.googlesource.com/1081668
Reviewed-by: Hector Carmona <hcarmona@chromium.org>
Commit-Queue: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#563479}

chrome/test/data/webui/cr_elements/cr_dialog_test.js

@@ -11,6 +11,34 @@ suite('cr-dialog', function() {
     PolymerTest.clearBody();
   });
 
+  test('close event bubbles', function() {
+    document.body.innerHTML = `
+      <cr-dialog>
+        <div slot="title">title</div>
+        <div slot="body">body</div>
+      </cr-dialog>`;
+
+    const dialog = document.body.querySelector('cr-dialog');
+    dialog.showModal();
+    const whenFired = test_util.eventToPromise('close', dialog);
+    dialog.close();
+    return whenFired;
+  });
+
+  test('cancel event bubbles', function() {
+    document.body.innerHTML = `
+      <cr-dialog>
+        <div slot="title">title</div>
+        <div slot="body">body</div>
+      </cr-dialog>`;
+
+    const dialog = document.body.querySelector('cr-dialog');
+    dialog.showModal();
+    const whenFired = test_util.eventToPromise('cancel', dialog);
+    dialog.cancel();
+    return whenFired;
+  });
+
   test('focuses title on show', function() {
     document.body.innerHTML = `
       <cr-dialog>

chrome/test/data/webui/cr_elements/cr_elements_browsertest.js

@@ -272,6 +272,7 @@ CrElementsDialogTest.prototype = {
 
   /** @override */
   extraLibraries: CrElementsBrowserTest.prototype.extraLibraries.concat([
+    '../settings/test_util.js',
     'cr_dialog_test.js',
   ]),
 };