Features are function names if they have a parent feature.

chrome/renderer/extensions/dispatcher.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/extensions/dispatcher.h"
 
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/debug/alias.h"
 #include "base/json/json_reader.h"
@@ skipping 732 matching lines @@
           it != apis.end(); ++it) {
         const std::string& api_name = *it;
         Feature* feature = api_feature_provider->GetFeature(api_name);
         DCHECK(feature);
 
         // Internal APIs are included via require(api_name) from internal code
         // rather than chrome[api_name].
         if (feature->IsInternal())
           continue;
 
-        // If this API name has parent features, then this must be a function or
-        // event, so we should not register.
-        bool parent_feature_available = false;
-        for (Feature* parent = api_feature_provider->GetParent(feature);
-             parent != NULL; parent = api_feature_provider->GetParent(parent)) {
-          if (context->IsAnyFeatureAvailableToContext(*parent)) {
-            parent_feature_available = true;
-            break;
-          }
-        }
-        if (parent_feature_available)
+        // If this API has a parent feature (and isn't marked 'noparent'),
+        // then this must be a function or event, so we should not register.
+        if (api_feature_provider->GetParent(feature) != NULL)
           continue;
 
         if (context->IsAnyFeatureAvailableToContext(*feature))
           RegisterBinding(api_name, context);
       }
       break;
     }
   }
 }
 
@@ skipping 882 matching lines @@
     RenderView* background_view =
         ExtensionHelper::GetBackgroundPage(extension_id);
     if (background_view) {
       background_view->Send(new ExtensionHostMsg_EventAck(
           background_view->GetRoutingID()));
     }
   }
 }
 
 }  // namespace extensions