Docserver: there is only one.

chrome/common/extensions/docs/static/js/platform_chooser.js

Index: chrome/common/extensions/docs/static/js/platform_chooser.js
diff --git a/chrome/common/extensions/docs/static/js/platform_chooser.js b/chrome/common/extensions/docs/static/js/platform_chooser.js
new file mode 100644
index 0000000000000000000000000000000000000000..fe1540e7fb0972ab62d88bd30366190ade4c3857
--- /dev/null
+++ b/chrome/common/extensions/docs/static/js/platform_chooser.js
@@ -0,0 +1,18 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Intializes the platform chooser, the widget in the top left corner with the
+// 'Apps...Extensions' dropdown.
+(function() {
+
+var platformChooser = document.getElementById('platform-chooser-popup');
+Array.prototype.forEach.call(platformChooser.getElementsByTagName('button'),
+                             function(button) {
+  button.addEventListener('click', function(event) {
+    window.location.assign(button.getAttribute('data-href'));
+    event.stopPropagation();
+  });
+});
+
+})()