Eliminate ChildThread InterfaceRegistry.

content/public/test/mock_render_thread.cc

Index: content/public/test/mock_render_thread.cc
diff --git a/content/public/test/mock_render_thread.cc b/content/public/test/mock_render_thread.cc
index f2f9b4279cd294d35945352cb3dee5a20c787a8b..99ff137ba2b79b099bfc098edc35e9aa19d8517e 100644
--- a/content/public/test/mock_render_thread.cc
+++ b/content/public/test/mock_render_thread.cc
@@ -19,9 +19,6 @@
 #include "ipc/ipc_sync_message.h"
 #include "ipc/message_filter.h"
 #include "services/service_manager/public/cpp/connector.h"
-#include "services/service_manager/public/cpp/interface_provider.h"
-#include "services/service_manager/public/cpp/interface_registry.h"
-#include "services/service_manager/public/interfaces/interface_provider_spec.mojom.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/WebKit/public/web/WebScriptController.h"
 
@@ -253,14 +250,6 @@ ServiceManagerConnection* MockRenderThread::GetServiceManagerConnection() {
   return nullptr;
 }
 
-service_manager::InterfaceRegistry* MockRenderThread::GetInterfaceRegistry() {
-  if (!interface_registry_) {
-    interface_registry_ = base::MakeUnique<service_manager::InterfaceRegistry>(
-        service_manager::mojom::kServiceManager_ConnectorSpec);
-  }
-  return interface_registry_.get();
-}
-
 service_manager::Connector* MockRenderThread::GetConnector() {
   if (!connector_) {
     connector_ =