Linux sandbox: restrict *kill to the current process.

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

Index: sandbox/linux/seccomp-bpf-helpers/syscall_sets.cc
diff --git a/sandbox/linux/seccomp-bpf-helpers/syscall_sets.cc b/sandbox/linux/seccomp-bpf-helpers/syscall_sets.cc
index 032f6c3c4721923193511d2bcacd8a302a125f21..792807ac72f4c1ee9d7d575e25247ac6cd1ab2b5 100644
--- a/sandbox/linux/seccomp-bpf-helpers/syscall_sets.cc
+++ b/sandbox/linux/seccomp-bpf-helpers/syscall_sets.cc
@@ -14,12 +14,11 @@ namespace sandbox {
 // The implicitly defined sets form a partition of the sets of
 // system calls.
 
-// TODO(jln) we need to restrict the first parameter!
 bool SyscallSets::IsKill(int sysno) {
   switch (sysno) {
     case __NR_kill:
-    case __NR_tkill:
     case __NR_tgkill:
+    case __NR_tkill:  // Deprecated.
       return true;
     default:
       return false;