Use ChannelMojo for the utility process.

content/child/child_thread_impl.cc

Index: content/child/child_thread_impl.cc
diff --git a/content/child/child_thread_impl.cc b/content/child/child_thread_impl.cc
index b5637ea05b724ab3c8cee177851bfd267ea2cf2c..4cd05b92ddf22e5024b255f97277c165c62b9db6 100644
--- a/content/child/child_thread_impl.cc
+++ b/content/child/child_thread_impl.cc
@@ -262,7 +262,8 @@ ChildThread* ChildThread::Get() {
 ChildThreadImpl::Options::Options()
     : channel_name(base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
           switches::kProcessChannelID)),
-      use_mojo_channel(false) {
+      use_mojo_channel(base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kMojoChannelToken)) {
 }
 
 ChildThreadImpl::Options::Options(const Options& other) = default;