Adding method to create process using LowBox token in sandbox code.

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index be9b91abfa5f8bd441bf5a3b4286ea968c9612bd..6b1a48b106acf148c628c386e21f9ad893e0722c 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -324,6 +324,9 @@ class RendererSandboxedProcessLauncherDelegate
   virtual void PreSpawnTarget(sandbox::TargetPolicy* policy,
                               bool* success) {
     AddBaseHandleClosePolicy(policy);
+
+    AddAppContainerPolicy(policy);
+
     GetContentClient()->browser()->PreSpawnRenderer(policy, success);
   }