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 e70252d52c8df501c258e89c3674d34e0d7851d5..3680c192af40568b9a3a9a9ca7513c9052884fb1 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;