build CrOS chrome with gn

mojo/runner/host/linux_sandbox.cc

Index: mojo/runner/host/linux_sandbox.cc
diff --git a/mojo/runner/host/linux_sandbox.cc b/mojo/runner/host/linux_sandbox.cc
index 23b844328e8adc7d662197edfbea0f4aad21d7ed..ac73ca904270970b91bf9bb1caa06d499095804d 100644
--- a/mojo/runner/host/linux_sandbox.cc
+++ b/mojo/runner/host/linux_sandbox.cc
@@ -83,7 +83,14 @@ class SandboxPolicy : public sandbox::BaselinePolicy {
       case __NR_sched_getaffinity:
         return sandbox::RestrictSchedTarget(policy_pid(), sysno);
       case __NR_ftruncate:
+#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: