Linux Sandbox: always discover Zygote PID properly

content/zygote/zygote_linux.cc

Index: content/zygote/zygote_linux.cc
diff --git a/content/zygote/zygote_linux.cc b/content/zygote/zygote_linux.cc
index 42dd5d8457f9a0bda85d79ee0b681f9cfc7629ff..5944f87aa1258dff7a908eb6d5a2d55cea93a05f 100644
--- a/content/zygote/zygote_linux.cc
+++ b/content/zygote/zygote_linux.cc
@@ -106,7 +106,7 @@ bool Zygote::ProcessRequests() {
   action.sa_handler = &SIGCHLDHandler;
   CHECK(sigaction(SIGCHLD, &action, NULL) == 0);
 
-  if (UsingSUIDSandbox()) {
+  if (UsingSUIDSandbox() || UsingNSSandbox()) {
     // Let the ZygoteHost know we are ready to go.
     // The receiving code is in content/browser/zygote_host_linux.cc.
     bool r = UnixDomainSocket::SendMsg(kZygoteSocketPairFd,
@@ -147,6 +147,10 @@ bool Zygote::UsingSUIDSandbox() const {
   return sandbox_flags_ & kSandboxLinuxSUID;
 }
 
+bool Zygote::UsingNSSandbox() const {
+  return sandbox_flags_ & kSandboxLinuxUserNS;
+}
+
 bool Zygote::HandleRequestFromBrowser(int fd) {
   ScopedVector<base::ScopedFD> fds;
   char buf[kZygoteMaxMessageLength];