build CrOS chrome with gn

mojo/runner/host/linux_sandbox.cc

 // 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 "mojo/runner/host/linux_sandbox.h"
 
 #include <fcntl.h>
 #include <sys/syscall.h>
 #include <utility>
 
@@ skipping 66 matching lines @@
     // This policy is only advisory/for noticing FS access for the moment.
     switch (sysno) {
       case __NR_access:
       case __NR_open:
       case __NR_faccessat:
       case __NR_openat:
         return sandbox::bpf_dsl::Trap(SandboxSIGSYSHandler, broker_process_);
       case __NR_sched_getaffinity:
         return sandbox::RestrictSchedTarget(policy_pid(), sysno);
       case __NR_ftruncate:
-#if defined(__NR_getrlimit)
-      // __NR_getrlimit does not exist on all systems (e.g. in the arm/linux
-      // build).
+#if defined(__i386__) || defined(__x86_64__) || defined(__mips__)
+      // Per #ifdefs in
+      // content/common/sandbox_linux/bpf_renderer_policy_linux.cc
       case __NR_getrlimit:
 #endif
+#if defined(__i386__) || defined(__arm__)
+      case __NR_ugetrlimit:
+#endif
       case __NR_uname:
       case __NR_getsockopt:
       case __NR_setsockopt:
         return sandbox::bpf_dsl::Allow();
     }
 
     return BaselinePolicy::EvaluateSyscall(sysno);
   }
 
  private:
@@ skipping 49 matching lines @@
   ALLOW_UNUSED_LOCAL(leaked_broker);
   ANNOTATE_LEAKING_OBJECT_PTR(leaked_broker);
 }
 
 void LinuxSandbox::Seal() {
   proc_fd_.reset();
 }
 
 }  // namespace runner
 }  // namespace mojo