diff -r 000000000000 -r 6474c204b198 layout/base/tests/enableTestPlugin.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/base/tests/enableTestPlugin.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,25 @@
+// this automatically sets the test plugin to be enabled (not e.g. click-to-play)
+// and resets this afterwards
+
+(function() {
+  function getTestPlugin(aPluginName) {
+    var ph = SpecialPowers.Cc["@mozilla.org/plugin/host;1"]
+                          .getService(SpecialPowers.Ci.nsIPluginHost);
+    var tags = ph.getPluginTags();
+    for (var tag of tags) {
+      if (tag.name == aPluginName) {
+       return tag;
+      }
+    }
+
+    ok(false, "Could not find plugin tag with plugin name '" + name + "'");
+    return null;
+  }
+
+  var plugin = getTestPlugin("Test Plug-in");
+  var oldEnabledState = plugin.enabledState;
+  plugin.enabledState = SpecialPowers.Ci.nsIPluginTag.STATE_ENABLED;
+  SimpleTest.registerCleanupFunction(function() {
+    getTestPlugin("Test Plug-in").enabledState = oldEnabledState;
+  });
+})();