Create a build_config header file.

tests/sel_main_chrome/sel_main_chrome_test.cc

 /*
  * Copyright (c) 2012 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include <fcntl.h>
 #include <cstring>
 
+#include "native_client/src/include/build_config.h"
 #if NACL_WINDOWS
 # include <io.h>
 #endif
 
 #include "native_client/src/public/chrome_main.h"
 #include "native_client/src/public/nacl_app.h"
 #include "native_client/src/public/nacl_file_info.h"
 #include "native_client/src/shared/platform/nacl_check.h"
 #include "native_client/src/shared/platform/nacl_threads.h"
 #include "native_client/src/shared/srpc/nacl_srpc.h"
@@ skipping 294 matching lines @@
   }
 
   NaClThread thread;
   CHECK(NaClThreadCtor(&thread, DummyRendererThread, &thread_args,
                        NACL_KERN_STACK_SIZE));
 
   NaClChromeMainStartApp(nap, args);
   NaClLog(LOG_FATAL, "NaClChromeMainStartApp() should never return\n");
   return 1;
 }