Linux Sandbox: move init processes to new session id.

sandbox/linux/suid/client/setuid_sandbox_client.cc

Index: sandbox/linux/suid/client/setuid_sandbox_client.cc
diff --git a/sandbox/linux/suid/client/setuid_sandbox_client.cc b/sandbox/linux/suid/client/setuid_sandbox_client.cc
index f0b5cef1e0068ef9c0ddc1deccf46786ade54a4a..8a50a3b2aeb2c428e1f59243016d15555d3b1467 100644
--- a/sandbox/linux/suid/client/setuid_sandbox_client.cc
+++ b/sandbox/linux/suid/client/setuid_sandbox_client.cc
@@ -208,6 +208,11 @@ bool SetuidSandboxClient::ChrootMe() {
   return true;
 }
 
+bool SetuidSandboxClient::CreateNewSession() {
+  // This could fail if the process is already a process group leader.
+  return 0 < setsid();
+}
+
 bool SetuidSandboxClient::CreateInitProcessReaper(
     base::Closure* post_fork_parent_callback) {
   return sandbox::CreateInitProcessReaper(post_fork_parent_callback);