Use the suid helper for oom_score_adj on Chrome OS.

content/browser/zygote_host/zygote_host_impl_linux.cc

Index: content/browser/zygote_host/zygote_host_impl_linux.cc
diff --git a/content/browser/zygote_host/zygote_host_impl_linux.cc b/content/browser/zygote_host/zygote_host_impl_linux.cc
index f439e0690da19ffecebbc5912d838b969e6ed791..5c964c531d3a946159c5997f2f8dc27658f1e483 100644
--- a/content/browser/zygote_host/zygote_host_impl_linux.cc
+++ b/content/browser/zygote_host/zygote_host_impl_linux.cc
@@ -163,6 +163,14 @@ void ZygoteHostImpl::Init(const std::string& sandbox_cmd) {
   use_suid_sandbox_for_adj_oom_score_ =
       !sandbox_binary_.empty() && using_suid_sandbox;
 
+#if defined(OS_CHROMEOS)
+  // Chrome OS has a kernel patch that restricts oom_score_adj. See
+  // crbug.com/576409 for details.
+  if (!sandbox_binary_.empty() && using_namespace_sandbox) {
+    use_suid_sandbox_for_adj_oom_score_ = true;
+  }
+#endif
+
   // Start up the sandbox host process and get the file descriptor for the
   // renderers to talk to it.
   const int sfd = RenderSandboxHostLinux::GetInstance()->GetRendererSocket();