Add routine to close file descriptors on exec

base/process_util_mac.mm

Index: base/process_util_mac.mm
diff --git a/base/process_util_mac.mm b/base/process_util_mac.mm
index 330e8b298729f5295c28786e0a94f54117c1aef7..a52f608af6a585a7b4fedb471d68cc3e0e90e364 100644
--- a/base/process_util_mac.mm
+++ b/base/process_util_mac.mm
@@ -31,13 +31,7 @@ bool LaunchApp(const std::vector<std::string>& argv,
 
   // Make sure we don't leak any FDs to the child process by marking all FDs
   // as close-on-exec.
-  int max_files = GetMaxFilesOpenInProcess();
-  for (int i = STDERR_FILENO + 1; i < max_files; i++) {
-    int flags = fcntl(i, F_GETFD);
-    if (flags != -1) {
-      fcntl(i, F_SETFD, flags | FD_CLOEXEC);
-    }
-  }
+  SetAllFDsToCloseOnExec();
 
   posix_spawn_file_actions_t file_actions;
   if (posix_spawn_file_actions_init(&file_actions) != 0) {