Add version-specific defines for each C interface.

ppapi/c/dev/ppb_directory_reader_dev.h

 /* Copyright (c) 2010 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 PPAPI_C_DEV_PPB_DIRECTORY_READER_DEV_H_
 #define PPAPI_C_DEV_PPB_DIRECTORY_READER_DEV_H_
 
 #include "ppapi/c/dev/pp_file_info_dev.h"
 #include "ppapi/c/pp_bool.h"
 #include "ppapi/c/pp_macros.h"
 #include "ppapi/c/pp_module.h"
 #include "ppapi/c/pp_resource.h"
 
 struct PP_CompletionCallback;
 
 struct PP_DirectoryEntry_Dev {
   PP_Resource file_ref;
   PP_FileType_Dev file_type;
 };
 PP_COMPILE_ASSERT_STRUCT_SIZE_IN_BYTES(PP_DirectoryEntry_Dev, 8);
 
-#define PPB_DIRECTORYREADER_DEV_INTERFACE "PPB_DirectoryReader(Dev);0.4"
+#define PPB_DIRECTORYREADER_DEV_INTERFACE_0_4 "PPB_DirectoryReader(Dev);0.4"
+#define PPB_DIRECTORYREADER_DEV_INTERFACE PPB_DIRECTORYREADER_DEV_INTERFACE_0_4
 
 struct PPB_DirectoryReader_Dev {
   // Creates a DirectoryReader for the given directory.  Upon success, the
   // corresponding directory is classified as "in use" by the resulting
   // DirectoryReader object until such time as the DirectoryReader object is
   // destroyed.
   PP_Resource (*Create)(PP_Resource directory_ref);
 
   // Returns PP_TRUE if the given resource is a DirectoryReader. Returns
   // PP_FALSE if the resource is invalid or some type other than a
@@ skipping 16 matching lines @@
   //   }
   //   core_funcs->ReleaseResource(reader);
   //
   int32_t (*GetNextEntry)(PP_Resource directory_reader,
                           struct PP_DirectoryEntry_Dev* entry,
                           struct PP_CompletionCallback callback);
 };
 
 #endif  /* PPAPI_C_DEV_PPB_DIRECTORY_READER_DEV_H_ */