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

ppapi/c/dev/ppb_char_set_dev.h

Index: ppapi/c/dev/ppb_char_set_dev.h
diff --git a/ppapi/c/dev/ppb_char_set_dev.h b/ppapi/c/dev/ppb_char_set_dev.h
index 26c3b2ef5e2a96f99663cf61c90b4e9f044e821c..0ad7de688dedbe88df0267c3ef53f779750883b0 100644
--- a/ppapi/c/dev/ppb_char_set_dev.h
+++ b/ppapi/c/dev/ppb_char_set_dev.h
@@ -35,7 +35,7 @@ enum PP_CharSet_ConversionError {
 };
 PP_COMPILE_ASSERT_ENUM_SIZE_IN_BYTES(PP_CharSet_ConversionError, 4);
 
-struct PPB_CharSet_Dev {
+struct PPB_CharSet_Dev_0_4 {
   // Converts the UTF-16 string pointed to in |*utf16| to an 8-bit string in the
   // specified code page. |utf16_len| is measured in UTF-16 units, not bytes.
   // This value may not be NULL.
@@ -80,5 +80,6 @@ struct PPB_CharSet_Dev {
   struct PP_Var (*GetDefaultCharSet)(PP_Instance instance);
 };
 
-#endif  /* PPAPI_C_DEV_PPB_CHAR_SET_DEV_H_ */
+typedef struct PPB_CharSet_Dev_0_4 PPB_CharSet_Dev;
 
+#endif  /* PPAPI_C_DEV_PPB_CHAR_SET_DEV_H_ */