Prepare for moving nacl_irt_icache definition to the NaCl repository.

ppapi/nacl_irt/public/irt_nonsfi.h

Index: ppapi/nacl_irt/public/irt_nonsfi.h
diff --git a/ppapi/nacl_irt/public/irt_nonsfi.h b/ppapi/nacl_irt/public/irt_nonsfi.h
index acc0eaccf902a09d5d9e28bf14c170844eedbb11..82d6635a01e8ab097935b39ec9b9cd1e3b8e8951 100644
--- a/ppapi/nacl_irt/public/irt_nonsfi.h
+++ b/ppapi/nacl_irt/public/irt_nonsfi.h
@@ -3,10 +3,15 @@
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
+// TODO(mazda): Remove this file once NaCl has been rolled to the revision
+// that includes the definition of nacl_irt_icache.
+// https://code.google.com/p/nativeclient/issues/detail?id=4033
 
 #ifndef PPAPI_NACL_IRT_PUBLIC_IRT_NONSFI_H_
 #define PPAPI_NACL_IRT_PUBLIC_IRT_NONSFI_H_
 
+#if !defined(NACL_IRT_ICACHE_v0_1)
+
 #include <stddef.h>
 
 /*
@@ -21,4 +26,6 @@ struct nacl_irt_icache {
   int (*clear_cache)(void* addr, size_t size);
 };
 
+#endif
+
 #endif  // PPAPI_NACL_IRT_PUBLIC_IRT_NONSFI_H_