--- base/process_util.h
+++ base/process_util.h
@@ -89,7 +89,7 @@ void CloseProcessHandle(ProcessHandle process);
 // Win XP SP1 as well.
 ProcessId GetProcId(ProcessHandle process);
 
-#if defined(OS_LINUX)
+#if defined(OS_NIX)
 // Returns the ID for the parent of the given process.
 ProcessId GetParentProcessId(ProcessHandle process);
 
@@ -412,7 +412,7 @@ class ProcessMetrics {
   int64 last_time_;
   int64 last_system_time_;
 
-#if defined(OS_LINUX)
+#if defined(OS_NIX)
   // Jiffie count at the last_time_ we updated.
   int last_cpu_;
 #endif
diff --git base/process_util_posix.cc base/process_util_posix.cc
index bfcd739..cd0e0c6 100644