Update from https://crrev.com/311145

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 8a50a3b2aeb2c428e1f59243016d15555d3b1467..f0b5cef1e0068ef9c0ddc1deccf46786ade54a4a 100644
--- a/sandbox/linux/suid/client/setuid_sandbox_client.cc
+++ b/sandbox/linux/suid/client/setuid_sandbox_client.cc
@@ -208,11 +208,6 @@ 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);