Add version-specific defines for each C interface.

ppapi/c/dev/ppb_font_list_dev.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_DEV_PPB_FONT_LIST_DEV_H_
 #define PPAPI_C_DEV_PPB_FONT_LIST_DEV_H_
 
 #include "ppapi/c/pp_completion_callback.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_resource.h"
 #include "ppapi/c/pp_var.h"
 
-#define PPB_FONT_LIST_DEV_INTERFACE "PPB_FontList(Dev);0.1"
+#define PPB_FONT_LIST_DEV_INTERFACE_0_1 "PPB_FontList(Dev);0.1"
+#define PPB_FONT_LIST_DEV_INTERFACE PPB_FONT_LIST_DEV_INTERFACE_0_1
 
 struct PPB_FontList_Dev {
   /* Creates a font list resource. By default, the list will be empty, you must
    * call Initialize before calling any other functions to actually populate
    * the fonts.
    */
   PP_Resource (*Create)(PP_Instance instance);
 
   /* Actually retrieves the fonts associated with this resource. This function
    * will complete asynchronously (it may be slow to get all of the fonts from
@@ skipping 12 matching lines @@
    * string var. Valid indices are [0, GetListSize). Passing an invalid
    * resource, an out-of-range index, or a FontList that has not issued its
    * create completion callback from Initialize() yet will result in a Null var
    * being returned.
    */
   struct PP_Var (*GetFontFaceAt)(PP_Resource font_list, int32_t index);
 };
 
 #endif  /* PPAPI_C_DEV_PPB_FONT_LIST_DEV_H_ */