Always use ChannelMojo for content child processes.

content/common/child_process_host_impl.cc

Index: content/common/child_process_host_impl.cc
diff --git a/content/common/child_process_host_impl.cc b/content/common/child_process_host_impl.cc
index f03402823bdf160a01cdb4e041fb42348763644e..23c339f2aa1bb5078e6843b23beca7eacfb5325a 100644
--- a/content/common/child_process_host_impl.cc
+++ b/content/common/child_process_host_impl.cc
@@ -173,16 +173,6 @@ void ChildProcessHostImpl::CreateChannelMojo() {
   DCHECK(initialized);
 }
 
-std::string ChildProcessHostImpl::CreateChannel() {
-  DCHECK(channel_id_.empty());
-  channel_id_ = IPC::Channel::GenerateVerifiedChannelID(std::string());
-  channel_ = IPC::Channel::CreateServer(channel_id_, this);
-  if (!channel_ || !InitChannel())
-    return std::string();
-
-  return channel_id_;
-}
-
 bool ChildProcessHostImpl::InitChannel() {
 #if USE_ATTACHMENT_BROKER
   DCHECK(base::MessageLoopForIO::IsCurrent());