Linux Sandbox: always discover Zygote PID properly

content/browser/zygote_host/zygote_host_impl_linux.cc

Index: content/browser/zygote_host/zygote_host_impl_linux.cc
diff --git a/content/browser/zygote_host/zygote_host_impl_linux.cc b/content/browser/zygote_host/zygote_host_impl_linux.cc
index 39c530fb14c634a249646776a6fedc1084e2edf7..5d53b888a9eda1ac80ca9b7ce9511d82e97a8d60 100644
--- a/content/browser/zygote_host/zygote_host_impl_linux.cc
+++ b/content/browser/zygote_host/zygote_host_impl_linux.cc
@@ -182,7 +182,7 @@ void ZygoteHostImpl::Init(const std::string& sandbox_cmd) {
 
   dummy_fd.reset();
 
-  if (using_suid_sandbox) {
+  if (using_suid_sandbox || using_namespace_sandbox) {
     // The SUID sandbox will execute the zygote in a new PID namespace, and
     // the main zygote process will then fork from there.  Watch now our
     // elaborate dance to find and validate the zygote's PID.