Port some of the base system to FreeBSD. Extracted from...

base/process_util.h

Index: base/process_util.h
===================================================================
--- base/process_util.h	(revision 24732)
+++ base/process_util.h	(working copy)
@@ -13,7 +13,11 @@
 #if defined(OS_WIN)
 #include <windows.h>
 #include <tlhelp32.h>
-#elif defined(OS_LINUX)
+#elif defined(OS_MACOSX)
+// kinfo_proc is defined in <sys/sysctl.h>, but this forward declaration
+// is sufficient for the vector<> below.
+struct kinfo_proc;
+#elif defined(OS_POSIX)
 #include <dirent.h>
 #include <limits.h>
 #include <sys/types.h>
@@ -50,10 +54,6 @@
 #include "base/file_descriptor_shuffle.h"
 #endif
 
-#if defined(OS_MACOSX)
-struct kinfo_proc;
-#endif
-
 namespace base {
 
 // A minimalistic but hopefully cross-platform set of exit codes.
@@ -273,11 +273,11 @@
 #if defined(OS_WIN)
   HANDLE snapshot_;
   bool started_iteration_;
-#elif defined(OS_LINUX)
-  DIR *procfs_dir_;
 #elif defined(OS_MACOSX)
   std::vector<kinfo_proc> kinfo_procs_;
   size_t index_of_kinfo_proc_;
+#elif defined(OS_POSIX)
+  DIR *procfs_dir_;
 #endif
   ProcessEntry entry_;
   const ProcessFilter* filter_;