NaCl: Fix a file to compile with -Wundef

ppapi/native_client/tests/ppapi_geturl/url_load_request.h

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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 TESTS_PPAPI_GETURL_URL_LOAD_REQUEST_H_
 #define TESTS_PPAPI_GETURL_URL_LOAD_REQUEST_H_
 
 #include <string>
 #include <vector>
 
 #include "ppapi/c/ppb_file_io.h"
 #include "ppapi/c/ppb_file_ref.h"
 #include "ppapi/c/ppb_url_loader.h"
 #include "ppapi/c/ppb_url_request_info.h"
 #include "ppapi/c/ppb_url_response_info.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_resource.h"
 #include "ppapi/c/pp_stdint.h"
-#if __native_client__
+#if defined(__native_client__)
 // TODO(polina): add file_io_nacl include
 #else
 #include "ppapi/c/trusted/ppb_file_io_trusted.h"
 #endif
 
 
 class UrlLoadRequest {
  public:
   explicit UrlLoadRequest(PP_Instance instance);
   ~UrlLoadRequest();
@@ skipping 41 matching lines @@
   const PPB_URLResponseInfo* response_interface_;
   const PPB_URLLoader* loader_interface_;
   const PPB_FileIO* fileio_interface_;
 
   char buffer_[1024];
   std::string url_body_;
   int32_t read_offset_;
 };
 
 #endif  // TESTS_PPAPI_GETURL_URL_LOAD_REQUEST_H_