Add sample extension that allows setting plugin-specific content settings.

chrome/common/extensions/docs/examples/extensions/plugin_settings/js/main.js

Index: chrome/common/extensions/docs/examples/extensions/plugin_settings/js/main.js
diff --git a/chrome/common/extensions/docs/examples/extensions/plugin_settings/js/main.js b/chrome/common/extensions/docs/examples/extensions/plugin_settings/js/main.js
new file mode 100644
index 0000000000000000000000000000000000000000..1b6156641d700530a874a48359f4680decec1099
--- /dev/null
+++ b/chrome/common/extensions/docs/examples/extensions/plugin_settings/js/main.js
@@ -0,0 +1,16 @@
+// Copyright (c) 2011 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.
+
+document.addEventListener('DOMContentLoaded', function() {
+  chrome.contentSettings.plugins.getResourceIdentifiers(function(r) {
+    if (chrome.extension.lastError) {
+      $('error').textContent =
+          "Error: " + chrome.extension.lastError.message;
+      return;

[Mike West, 2011/10/25 19:52:06]

This means that if the extension ever errors out, the user won't be able to fix
it (as the plugin list is never initialized, etc.). Is that intentional?

It would probably be a good idea to fiddle with this such that the error message
is displayed, but the options page is still functional, which might be as simple
as dropping the `return`.

[Bernhard Bauer, 2011/10/26 13:55:18]

I'm not sure there would be much to fix in that case ;-) All the options page
displays is a list of plug-ins with rules for them, so if we don't get a list of
plug-ins, we wouldn't have anything to show anyway.

+    }
+    var pluginList = $('plugin-list');
+    pluginSettings.ui.PluginList.decorate(pluginList);
+    pluginList.dataModel = new cr.ui.ArrayDataModel(r);
+  });
+});