Create implementation of the side panel using a dialog.

chrome/test/data/webui/settings/settings_ui_browsertest.js

Index: chrome/test/data/webui/settings/settings_ui_browsertest.js
diff --git a/chrome/test/data/webui/settings/settings_ui_browsertest.js b/chrome/test/data/webui/settings/settings_ui_browsertest.js
index c4d919f1a564090b3063b66d76d2d8223eae8a8b..809f0ac18339d755ef3ba68dc75aeae58bad436b 100644
--- a/chrome/test/data/webui/settings/settings_ui_browsertest.js
+++ b/chrome/test/data/webui/settings/settings_ui_browsertest.js
@@ -47,7 +47,7 @@ TEST_F('SettingsUIBrowserTest', 'MAYBE_All', function() {
 
     test('app drawer', function(done) {
       assertEquals(null, ui.$$('settings-menu'));
-      var drawer = assert(ui.$$('app-drawer'));
+      var drawer = ui.$.drawer;
       assertFalse(drawer.opened);
 
       // Slide the drawer partway open. (These events are copied from Polymer's
@@ -71,7 +71,14 @@ TEST_F('SettingsUIBrowserTest', 'MAYBE_All', function() {
       assertTrue(drawer.opened);
 
       // Click away from the drawer.
-      MockInteractions.tap(drawer.$.scrim);
+      // MockInteractions don't expose a way to click at a specific location.
+      var midScreen = MockInteractions.middleOfNode(ui);
+      drawer.$.contentContainer.dispatchEvent(new MouseEvent('click', {
+        'bubbles': true,
+        'concelable': true,
+        'clientX': midScreen.x,
+        'clientY': midScreen.y,
+      }));
       Polymer.Base.async(function() {
         // Drawer is closed, but menu is still stamped so its contents remain
         // visible as the drawer slides out.