MD WebUI: Reimplement cr-shared-menu using iron-dropdown.

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

Index: chrome/test/data/webui/cr_elements/cr_elements_browsertest.js
diff --git a/chrome/test/data/webui/cr_elements/cr_elements_browsertest.js b/chrome/test/data/webui/cr_elements/cr_elements_browsertest.js
index 4e13fcde85be77fdbe0856ac0f93a0dc92eabc8e..bdce700a32247e2a45011001f77c989300ed7bb4 100644
--- a/chrome/test/data/webui/cr_elements/cr_elements_browsertest.js
+++ b/chrome/test/data/webui/cr_elements/cr_elements_browsertest.js
@@ -96,3 +96,23 @@ TEST_F('CrElementsSliderTest', 'All', function() {
   cr_slider.registerTests();
   mocha.run();
 });
+
+function CrElementsSharedMenuTest() {}
+
+CrElementsSharedMenuTest.prototype = {
+  __proto__: CrElementsBrowserTest.prototype,
+
+  /** @override */
+  browsePreload:
+      'chrome://resources/cr_elements/cr_shared_menu/cr_shared_menu.html',
+
+  /** @override */
+  extraLibraries: CrElementsBrowserTest.prototype.extraLibraries.concat([
+    'cr_shared_menu_tests.js'
+  ]),
+};
+
+TEST_F('CrElementsSharedMenuTest', 'All', function() {
+  cr_shared_menu.registerTests();
+  mocha.run();
+});