Add PDF compositor service

content/browser/service_manager/service_manager_context.cc

Index: content/browser/service_manager/service_manager_context.cc
diff --git a/content/browser/service_manager/service_manager_context.cc b/content/browser/service_manager/service_manager_context.cc
index 98372cb93d81786d264e1d9ed7df2d3c4e1ec4ca..a68e79b7d7cabbe6c49b5766b01d615dc73e82d5 100644
--- a/content/browser/service_manager/service_manager_context.cc
+++ b/content/browser/service_manager/service_manager_context.cc
@@ -4,6 +4,7 @@
 
 #include "content/browser/service_manager/service_manager_context.h"
 
+#include <map>
 #include <memory>
 #include <string>
 #include <utility>
@@ -70,6 +71,11 @@ void StartServiceInUtilityProcess(
   if (!use_sandbox)
     process_host->DisableSandbox();
   process_host->Start();
+  // Register mojo interfaces on UI thread.
+  BrowserThread::GetTaskRunnerForThread(BrowserThread::UI)
+      ->PostTask(FROM_HERE,
+                 base::Bind(&UtilityProcessHost::RegisterMojoServices,
+                            base::Unretained(process_host)));
   service_manager::mojom::ServiceFactoryPtr service_factory;
   BindInterface(process_host, mojo::MakeRequest(&service_factory));
   service_factory->CreateService(std::move(request), service_name);