Update from https://crrev.com/327068

sandbox/linux/seccomp-bpf/trap_unittest.cc

Index: sandbox/linux/seccomp-bpf/trap_unittest.cc
diff --git a/sandbox/linux/seccomp-bpf/trap_unittest.cc b/sandbox/linux/seccomp-bpf/trap_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3d95e3463ba75d85fff28f142c0666a2271471c9
--- /dev/null
+++ b/sandbox/linux/seccomp-bpf/trap_unittest.cc
@@ -0,0 +1,30 @@
+// Copyright 2015 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.
+
+#include "sandbox/linux/seccomp-bpf/trap.h"
+
+#include <signal.h>
+
+#include "sandbox/linux/tests/unit_tests.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace sandbox {
+namespace {
+
+#if !defined(THREAD_SANITIZER)
+SANDBOX_TEST_ALLOW_NOISE(Trap, SigSysAction) {
+  // This creates a global Trap instance, and registers the signal handler
+  // (Trap::SigSysAction).
+  Trap::Registry();
+
+  // Send SIGSYS to self. If signal handler (SigSysAction) is not registered,
+  // the process will be terminated with status code -SIGSYS.
+  // Note that, SigSysAction handler would output an error message
+  // "Unexpected SIGSYS received." so it is necessary to allow the noise.
+  raise(SIGSYS);
+}
+#endif
+
+}  // namespace
+}  // namespace sandbox