Generate java bindings for structs.

mojo/public/interfaces/bindings/tests/math_calculator.mojom

 // Copyright 2013 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.
 
-[JavaPackage="org.chromium.mojo.bindings.test.math"]
+[JavaPackage="org.chromium.mojo.bindings.test.mojom.math"]
 module math {
 
 [Client=CalculatorUI]
 interface Calculator {
   Clear@0();
   Add@1(double value@0);
   Multiply@2(double value@0);
 };
 
 interface CalculatorUI {
   Output@0(double value@0);
 };
 
 }