Add version-specific defines for each C interface.

ppapi/c/ppb_url_request_info.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 PPAPI_C_PPB_URL_REQUEST_INFO_H_
 #define PPAPI_C_PPB_URL_REQUEST_INFO_H_
 
 #include "ppapi/c/pp_bool.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_macros.h"
@@ skipping 106 matching lines @@
    * custom content transfer encoding; if given to a loader without universal
    * access, PP_ERROR_BADARGUMENT will result.
    */
   PP_URLREQUESTPROPERTY_CUSTOMCONTENTTRANSFERENCODING
 } PP_URLRequestProperty;
 PP_COMPILE_ASSERT_SIZE_IN_BYTES(PP_URLRequestProperty, 4);
 /**
  * @}
  */
 
-#define PPB_URLREQUESTINFO_INTERFACE "PPB_URLRequestInfo;0.2"
+#define PPB_URLREQUESTINFO_INTERFACE_0_2 "PPB_URLRequestInfo;0.2"
+#define PPB_URLREQUESTINFO_INTERFACE PPB_URLREQUESTINFO_INTERFACE_0_2
 
 /**
  *
  * @addtogroup Interfaces
  * @{
  */
 
 /**
  * The PPB_URLRequestInfo interface contains pointers to functions for creating
  * and handling URL requests. Refer to PPB_URLLoader for further information.
@@ skipping 79 matching lines @@
                               int64_t start_offset,
                               int64_t number_of_bytes,
                               PP_Time expected_last_modified_time);
 };
 /**
  * @}
  */
 
 #endif  /* PPAPI_C_PPB_URL_REQUEST_INFO_H_ */