MD Bookmarks: Fix Meta-down not triggering the 'Open' command on Mac

chrome/test/data/webui/md_bookmarks/command_manager_test.js

Index: chrome/test/data/webui/md_bookmarks/command_manager_test.js
diff --git a/chrome/test/data/webui/md_bookmarks/command_manager_test.js b/chrome/test/data/webui/md_bookmarks/command_manager_test.js
index 61ff0f85b6a41da3ce75ab74c125d3868860b67b..da428c25b1ae4757960a3182b218c1fd4f77baa4 100644
--- a/chrome/test/data/webui/md_bookmarks/command_manager_test.js
+++ b/chrome/test/data/webui/md_bookmarks/command_manager_test.js
@@ -382,4 +382,13 @@ suite('<bookmarks-item> CommandManager integration', function() {
 
     assertOpenedTabs(['http://111/', 'http://13/']);
   });
+
+  test('meta-down triggers Open on Mac', function() {
+    if (!cr.isMac)
+      return;
+
+    customClick(items[0]);
+    MockInteractions.pressAndReleaseKeyOn(items[0], 0, 'meta', 'ArrowDown');
+    assertEquals('11', store.data.selectedFolder);
+  });
 });