Enable sandbox in local discovery utility process.

content/browser/utility_process_host_impl.cc

Index: content/browser/utility_process_host_impl.cc
diff --git a/content/browser/utility_process_host_impl.cc b/content/browser/utility_process_host_impl.cc
index bf656748f02447ab591f1a242f71204a4ea9e669..6e9dfa725d75f3d6f98e0fecadef85e91dc6efba 100644
--- a/content/browser/utility_process_host_impl.cc
+++ b/content/browser/utility_process_host_impl.cc
@@ -111,6 +111,7 @@ UtilityProcessHostImpl::UtilityProcessHostImpl(
     : client_(client),
       client_task_runner_(client_task_runner),
       is_batch_mode_(false),
+      is_mdns_enabled_(false),
       no_sandbox_(false),
 #if defined(OS_LINUX)
       child_flags_(ChildProcessHost::CHILD_ALLOW_SELF),
@@ -123,7 +124,8 @@ UtilityProcessHostImpl::UtilityProcessHostImpl(
 
 UtilityProcessHostImpl::~UtilityProcessHostImpl() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  DCHECK(!is_batch_mode_);
+  if (is_batch_mode_)
+    EndBatchMode();
 }
 
 bool UtilityProcessHostImpl::Send(IPC::Message* message) {
@@ -150,6 +152,10 @@ void UtilityProcessHostImpl::SetExposedDir(const base::FilePath& dir) {
   exposed_dir_ = dir;
 }
 
+void UtilityProcessHostImpl::EnableMDns() {
+  is_mdns_enabled_ = true;
+}
+
 void UtilityProcessHostImpl::DisableSandbox() {
   no_sandbox_ = true;
 }
@@ -244,6 +250,9 @@ bool UtilityProcessHostImpl::StartProcess() {
     cmd_line->AppendSwitchPath(switches::kUtilityProcessAllowedDir, exposed_dir_);
 #endif
 
+    if (is_mdns_enabled_)
+      cmd_line->AppendSwitch(switches::kUtilityProcessEnableMDns);
+
     bool use_zygote = false;
 
 #if defined(OS_LINUX)