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

ppapi/tests/test_audio.h

Index: ppapi/tests/test_audio.h
diff --git a/ppapi/tests/test_audio.h b/ppapi/tests/test_audio.h
index 61ebc4213b75d6c7ef0a693da76536303b15cda2..4754fd0135a21e33d3f3f0e933f9795399994878 100644
--- a/ppapi/tests/test_audio.h
+++ b/ppapi/tests/test_audio.h
@@ -7,12 +7,11 @@
 
 #include <string>
 
+#include "ppapi/c/ppb_audio.h"
+#include "ppapi/c/ppb_audio_config.h"
+#include "ppapi/c/ppb_core.h"
 #include "ppapi/tests/test_case.h"
 
-struct PPB_Audio;
-struct PPB_AudioConfig;
-struct PPB_Core;
-
 class TestAudio : public TestCase {
  public:
   explicit TestAudio(TestingInstance* instance) : TestCase(instance) {}