Set the default visibility for __asan_default_options.

base/debug/sanitizer_options.cc

Index: base/debug/sanitizer_options.cc
diff --git a/base/debug/sanitizer_options.cc b/base/debug/sanitizer_options.cc
index 4dc6d17d94301d63e41f66027fc6b6633bf55324..a8a94594edbb2ee65f45644fd0e27349eb31751b 100644
--- a/base/debug/sanitizer_options.cc
+++ b/base/debug/sanitizer_options.cc
@@ -58,6 +58,10 @@ const char *kAsanDefaultOptions =
 #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;
 }