Revert of Eliminate ChildThread InterfaceRegistry.

content/public/child/child_thread.h

Index: content/public/child/child_thread.h
diff --git a/content/public/child/child_thread.h b/content/public/child/child_thread.h
index 575ee80807c953602613f52a0142e718880f41f0..9287ee8ac76df71640bf28fc954f72059dd05a65 100644
--- a/content/public/child/child_thread.h
+++ b/content/public/child/child_thread.h
@@ -22,6 +22,7 @@
 
 namespace service_manager {
 class Connector;
+class InterfaceRegistry;
 }
 
 namespace content {
@@ -70,6 +71,10 @@
   // service_manager::Connector can be obtained).
   virtual ServiceManagerConnection* GetServiceManagerConnection() = 0;
 
+  // Returns the InterfaceRegistry that this process uses to expose interfaces
+  // to the browser.
+  virtual service_manager::InterfaceRegistry* GetInterfaceRegistry() = 0;
+
   // Returns a connector that can be used to bind interfaces exposed by other
   // services.
   virtual service_manager::Connector* GetConnector() = 0;