diff -r 000000000000 -r 6474c204b198 mobile/android/base/mozglue/generatorannotations/OptionalGeneratedParameter.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/mozglue/generatorannotations/OptionalGeneratedParameter.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,18 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.mozglue.generatorannotations;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+/**
+ * Used to annotate parameters which are optional on the C++ side of the bridge. The annotation is
+ * used by the annotation processor to generate the appropriate C++ headers so calls into the Java
+ * method all have the optional params set to the default value.
+ * The default values are zero for numerical types, false for booleans, "" for strings, and null
+ * for all other reference types.
+ */
+@Retention(RetentionPolicy.RUNTIME)
+public @interface OptionalGeneratedParameter {}