[MIPS] Fix seccomp-bpf compile error for MIPS

sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.cc

 // Copyright (c) 2013 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.
 
 // Note: any code in this file MUST be async-signal safe.
 
 #include "sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.h"
 
 #include <unistd.h>
 
 #include "base/basictypes.h"
 #include "base/posix/eintr_wrapper.h"
 #include "build/build_config.h"
 #include "sandbox/linux/seccomp-bpf/sandbox_bpf.h"
 
+#if defined(__mips__)
+// __NR_Linux, is defined in <asm/unistd.h>.
+#include <asm/unistd.h>
+#endif
+
 #define SECCOMP_MESSAGE_COMMON_CONTENT "seccomp-bpf failure"
 #define SECCOMP_MESSAGE_CLONE_CONTENT "clone() failure"
 #define SECCOMP_MESSAGE_PRCTL_CONTENT "prctl() failure"
 #define SECCOMP_MESSAGE_IOCTL_CONTENT "ioctl() failure"
 #define SECCOMP_MESSAGE_KILL_CONTENT "(tg)kill() failure"
 #define SECCOMP_MESSAGE_FUTEX_CONTENT "futex() failure"
 
 namespace {
 
 inline bool IsArchitectureX86_64() {
@@ skipping 217 matching lines @@
 
 const char* GetKillErrorMessageContentForTests() {
   return SECCOMP_MESSAGE_KILL_CONTENT;
 }
 
 const char* GetFutexErrorMessageContentForTests() {
   return SECCOMP_MESSAGE_FUTEX_CONTENT;
 }
 
 }  // namespace sandbox.