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

ppapi/tests/test_flash.h

Index: ppapi/tests/test_flash.h
diff --git a/ppapi/tests/test_flash.h b/ppapi/tests/test_flash.h
index 5dfed88aa789524fd3bd483a852c40f3e6f45737..03775df7edff9efd6214ab4a6baf70aa80c6b207 100644
--- a/ppapi/tests/test_flash.h
+++ b/ppapi/tests/test_flash.h
@@ -9,10 +9,9 @@
 
 #include "ppapi/cpp/completion_callback.h"
 #include "ppapi/c/pp_stdint.h"
+#include "ppapi/c/private/ppb_flash.h"
 #include "ppapi/tests/test_case.h"
 
-struct PPB_Flash;
-
 class TestFlash : public TestCase {
  public:
   explicit TestFlash(TestingInstance* instance);