Linux sandbox: modify GYP files to compile under Android.

sandbox/linux/seccomp-bpf/sandbox_bpf_unittest.cc

Index: sandbox/linux/seccomp-bpf/sandbox_bpf_unittest.cc
diff --git a/sandbox/linux/seccomp-bpf/sandbox_bpf_unittest.cc b/sandbox/linux/seccomp-bpf/sandbox_bpf_unittest.cc
index f3952b0a8f18aa3b2a7c0975d42d381691752929..25b6655e02bf79b1fa9014079c85bc2730c28c89 100644
--- a/sandbox/linux/seccomp-bpf/sandbox_bpf_unittest.cc
+++ b/sandbox/linux/seccomp-bpf/sandbox_bpf_unittest.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include <sys/prctl.h>
+#include <sys/syscall.h>
 #include <sys/utsname.h>
 
 #include <ostream>
@@ -12,6 +12,7 @@
 #include "sandbox/linux/seccomp-bpf/syscall.h"
 #include "sandbox/linux/seccomp-bpf/verifier.h"
 #include "sandbox/linux/services/broker_process.h"
+#include "sandbox/linux/services/linux_syscalls.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using namespace playground2;