[Extensions Bindings] Add activity logging of custom handling

extensions/renderer/bindings/api_bindings_system.h

Index: extensions/renderer/bindings/api_bindings_system.h
diff --git a/extensions/renderer/bindings/api_bindings_system.h b/extensions/renderer/bindings/api_bindings_system.h
index 00d205f9271a96a20de7077180a4f68fc4c0823c..82351c3fd6645d3f6cb64e4206ccfd08f61e5299 100644
--- a/extensions/renderer/bindings/api_bindings_system.h
+++ b/extensions/renderer/bindings/api_bindings_system.h
@@ -51,6 +51,7 @@ class APIBindingsSystem {
       const APIRequestHandler::SendRequestMethod& send_request,
       const APIEventHandler::EventListenersChangedMethod&
           event_listeners_changed,
+      const APIBinding::OnSilentRequest& on_silent_request,
       APILastError last_error);
   ~APIBindingsSystem();
 
@@ -141,6 +142,10 @@ class APIBindingsSystem {
   // API. Curried in for testing purposes so we can use fake APIs.
   GetAPISchemaMethod get_api_schema_;
 
+  // The method to call when the system silently handles an API request without
+  // notifying the browser.
+  APIBinding::OnSilentRequest on_silent_request_;
+
   DISALLOW_COPY_AND_ASSIGN(APIBindingsSystem);
 };