Index: content/child/BUILD.gn
--- content/child/BUILD.gn.orig
+++ content/child/BUILD.gn
@@ -134,6 +134,13 @@ target(link_target_type, "child") {
     ]
   }
 
+  if (is_bsd) {
+    sources -= [
+      "sandboxed_process_thread_type_handler.cc",
+      "sandboxed_process_thread_type_handler.h",
+    ]
+  }
+
   if (is_win) {
     sources += [
       "child_process_sandbox_support_impl_win.cc",
