Demo: Build NamespaceSandbox::ForkInNewPidNamespace.

base/process/launch_posix.cc

Index: base/process/launch_posix.cc
diff --git a/base/process/launch_posix.cc b/base/process/launch_posix.cc
index 77edc1283191c9a6ad77b9a323cbd9cdf7d00153..f7f75a441b338fec4ec98256306beec5c7bd19dc 100644
--- a/base/process/launch_posix.cc
+++ b/base/process/launch_posix.cc
@@ -67,6 +67,7 @@ namespace base {
 
 namespace {
 
+#if !defined(OS_NACL_NONSFI)
 // Get the process's "environment" (i.e. the thing that setenv/getenv
 // work with).
 char** GetEnvironment() {
@@ -189,7 +190,9 @@ void ResetChildSignalHandlersToDefaults(void) {
 #endif  // !defined(OS_LINUX) ||
         // (!defined(__i386__) && !defined(__x86_64__) && !defined(__arm__))
 
-#if defined(OS_LINUX)
+#endif  // !defined(OS_NACL_NONSFI)
+
+#if defined(OS_LINUX) || defined(OS_NACL_NONSFI)
 bool IsRunningOnValgrind() {
   return RUNNING_ON_VALGRIND;
 }
@@ -235,10 +238,11 @@ NOINLINE pid_t CloneAndLongjmpInChild(unsigned long flags,
 #endif
   return clone(&CloneHelper, stack, flags, env, ptid, nullptr, ctid);
 }
-#endif  // defined(OS_LINUX)
+#endif  // defined(OS_LINUX) || defined(OS_NACL_NONSFI)
 
 }  // anonymous namespace
 
+#if !defined(OS_NACL_NONSFI)
 // Functor for |ScopedDIR| (below).
 struct ScopedDIRClose {
   inline void operator()(DIR* x) const {
@@ -741,7 +745,9 @@ bool GetAppOutputWithExitCode(const CommandLine& cl,
   return result == EXECUTE_SUCCESS;
 }
 
-#if defined(OS_LINUX)
+#endif  // !defined(OS_NACL_NONSFI)
+
+#if defined(OS_LINUX) || defined(OS_NACL_NONSFI)
 pid_t ForkWithFlags(unsigned long flags, pid_t* ptid, pid_t* ctid) {
   const bool clone_tls_used = flags & CLONE_SETTLS;
   const bool invalid_ctid =
@@ -780,6 +786,6 @@ pid_t ForkWithFlags(unsigned long flags, pid_t* ptid, pid_t* ctid) {
 
   return 0;
 }
-#endif  // defined(OS_LINUX)
+#endif  // defined(OS_LINUX) || defined(OS_NACL_NONSFI)
 
 }  // namespace base