Use ChannelMojo for the utility process.

content/common/child_process_host_impl.h

Index: content/common/child_process_host_impl.h
diff --git a/content/common/child_process_host_impl.h b/content/common/child_process_host_impl.h
index 18875c94e67028db164d96d82c55bb1e7d74dfc8..686a7737319084a00491a8e3161508443ad6a6ff 100644
--- a/content/common/child_process_host_impl.h
+++ b/content/common/child_process_host_impl.h
@@ -79,6 +79,7 @@ class CONTENT_EXPORT ChildProcessHostImpl : public ChildProcessHost,
   bool Send(IPC::Message* message) override;
   void ForceShutdown() override;
   std::string CreateChannel() override;
+  std::string CreateChannelMojo(const std::string& child_token) override;
   bool IsChannelOpening() override;
   void AddFilter(IPC::MessageFilter* filter) override;
 #if defined(OS_POSIX)
@@ -109,6 +110,10 @@ class CONTENT_EXPORT ChildProcessHostImpl : public ChildProcessHost,
   void OnDeletedGpuMemoryBuffer(gfx::GpuMemoryBufferId id,
                                 const gpu::SyncToken& sync_token);
 
+  // Initializes the IPC channel and returns true on success. |channel_| must be
+  // non-null.
+  bool InitChannel();
+
   ChildProcessHostDelegate* delegate_;
   base::Process peer_process_;
   bool opening_channel_;  // True while we're waiting the channel to be opened.