Update sandbox/linux from upstream

sandbox/linux/sandbox_linux.gypi

Index: sandbox/linux/sandbox_linux.gypi
diff --git a/sandbox/linux/sandbox_linux.gypi b/sandbox/linux/sandbox_linux.gypi
index a7bd259d8a9cc7ee35184104040cfcc63b27f05a..1958258144d0a5ec406389158b5ba341b7fed137 100644
--- a/sandbox/linux/sandbox_linux.gypi
+++ b/sandbox/linux/sandbox_linux.gypi
@@ -137,6 +137,8 @@
         'bpf_dsl/cons.h',
         'bpf_dsl/dump_bpf.cc',
         'bpf_dsl/dump_bpf.h',
+        'bpf_dsl/errorcode.cc',
+        'bpf_dsl/errorcode.h',
         'bpf_dsl/linux_syscall_ranges.h',
         'bpf_dsl/policy.cc',
         'bpf_dsl/policy.h',
@@ -151,8 +153,6 @@
         'bpf_dsl/verifier.h',
         'seccomp-bpf/die.cc',
         'seccomp-bpf/die.h',
-        'seccomp-bpf/errorcode.cc',
-        'seccomp-bpf/errorcode.h',
         'seccomp-bpf/sandbox_bpf.cc',
         'seccomp-bpf/sandbox_bpf.h',
         'seccomp-bpf/syscall.cc',
@@ -310,7 +310,8 @@
     },
     {
       # We make this its own target so that it does not interfere
-      # with our tests.
+      # with our tests, and so that it may be selectively included
+      # in ports which need it.
       'target_name': 'libc_urandom_override',
       'type': 'static_library',
       'sources': [