[Linux] Use PR_SET_NO_NEW_PRIVS by default in base/process/launch.h.

base/process/launch.h

Index: base/process/launch.h
diff --git a/base/process/launch.h b/base/process/launch.h
index d725e05eced8606dafbc3e7134814684e195912b..421982ff72a4c841f7847dffdb13dcd981b74d11 100644
--- a/base/process/launch.h
+++ b/base/process/launch.h
@@ -111,6 +111,10 @@ struct BASE_EXPORT LaunchOptions {
 #if defined(OS_LINUX)
   // If non-zero, start the process using clone(), using flags as provided.
   int clone_flags;
+
+  // By default, child processes will have the PR_SET_NO_NEW_PRIVS bit set. If
+  // true, then this bit will not be set in the new child process.
+  bool allow_new_privs;
 #endif  // defined(OS_LINUX)
 
 #if defined(OS_CHROMEOS)