Add PDF compositor service

content/public/browser/utility_process_host.h

Index: content/public/browser/utility_process_host.h
diff --git a/content/public/browser/utility_process_host.h b/content/public/browser/utility_process_host.h
index 5a404dbec1112aad88ed313fba155b8d18d75658..03d76d107a6583f456674f2ea23e166c24fff4a9 100644
--- a/content/public/browser/utility_process_host.h
+++ b/content/public/browser/utility_process_host.h
@@ -85,6 +85,10 @@ class UtilityProcessHost : public IPC::Sender {
   virtual void BindInterface(const std::string& interface_name,
                              mojo::ScopedMessagePipeHandle interface_pipe) = 0;
 
+  // Register mojo services that the utility process can use.
+  // This runs on UI thread.
+  virtual void RegisterMojoServices() = 0;
+
   // Set the name of the process to appear in the task manager.
   virtual void SetName(const base::string16& name) = 0;
 };