Set the default visibility for __asan_default_options.

base/debug/sanitizer_options.cc

 // Copyright 2014 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.
 //
 // This file contains the default options for various compiler-based dynamic
 // tools.
 
 #include "build/build_config.h"
 
 // Functions returning default options are declared weak in the tools' runtime
@@ skipping 40 matching lines @@
 #endif  // GOOGLE_CHROME_BUILD
 
 #elif defined(OS_MACOSX)
 const char *kAsanDefaultOptions =
     "strict_memcmp=0 replace_intrin=0 check_printf=1";
 #endif  // OS_LINUX
 
 #if defined(OS_LINUX) || defined(OS_MACOSX)
 extern "C"
 __attribute__((no_sanitize_address))
+__attribute__((visibility("default")))
+// The function isn't referenced from the executable itself. Make sure it isn't
+// stripped by the linker.
+__attribute__((used))
 const char *__asan_default_options() {
   return kAsanDefaultOptions;
 }
 #endif  // OS_LINUX || OS_MACOSX
 #endif  // ADDRESS_SANITIZER