Update PPAPI IDL generator to define versioned structs, and unversioned typedef.

ppapi/tests/test_buffer.h

 // 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.
 
 #ifndef PAPPI_TESTS_TEST_BUFFER_H_
 #define PAPPI_TESTS_TEST_BUFFER_H_
 
 #include <string>
 
+#include "ppapi/c/dev/ppb_buffer_dev.h"
 #include "ppapi/tests/test_case.h"
 
-struct PPB_Buffer_Dev;
-
 class TestBuffer : public TestCase {
  public:
   explicit TestBuffer(TestingInstance* instance) : TestCase(instance) {}
 
   // TestCase implementation.
   virtual bool Init();
   virtual void RunTests(const std::string& filter);
 
  private:
   std::string TestInvalidSize();
   std::string TestInitToZero();
   std::string TestIsBuffer();
   std::string TestBasicLifeCycle();
 
   // Used by the tests that access the C API directly.
   const PPB_Buffer_Dev* buffer_interface_;
 };
 
 #endif  // PAPPI_TESTS_TEST_BUFFER_H_