Features are function names if they have a parent feature.

chrome/renderer/extensions/dispatcher.cc

Index: chrome/renderer/extensions/dispatcher.cc
diff --git a/chrome/renderer/extensions/dispatcher.cc b/chrome/renderer/extensions/dispatcher.cc
index da0d23efd8c8f137c06b0f3e36ff20cdcf2c08db..05785c8f897569006261002ef046862bf8f81e7e 100644
--- a/chrome/renderer/extensions/dispatcher.cc
+++ b/chrome/renderer/extensions/dispatcher.cc
@@ -750,17 +750,9 @@ void Dispatcher::AddOrRemoveBindingsForContext(ChromeV8Context* context) {
         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.

[not at google - send to devlin, 2013/12/18 02:15:22]

yak shave:

a check which would make me feel more confident about this change is that we
don't load any bindings until after the context has been initiated. this is
actually what prompted this noparent stuff: we had lazy bindings for "app" and
"app.window", and when setting up the "app.window" binding it would
inadvertently load the "app" binding, which broke things.

I would even go so far as to say that no lazily initialised code should ever be
run during DidCreateScriptContext, and you could implement that similar to
ModuleSystem::NativesAllowedScope (or whatever it's called).

+        if (api_feature_provider->GetParent(feature) != NULL)
           continue;
 
         if (context->IsAnyFeatureAvailableToContext(*feature))