Add support for CallbackPromiseAdapter<void, T> matching WebCallbacks<void, T>.

Source/modules/geofencing/Geofencing.cpp

Index: Source/modules/geofencing/Geofencing.cpp
diff --git a/Source/modules/geofencing/Geofencing.cpp b/Source/modules/geofencing/Geofencing.cpp
index 8091f64903b8a05720e2722d55069b490f931408..9cc6c8a3c0012c69be1fa7bfb9c37005dee119e9 100644
--- a/Source/modules/geofencing/Geofencing.cpp
+++ b/Source/modules/geofencing/Geofencing.cpp
@@ -19,25 +19,6 @@ namespace blink {
 
 namespace {
 
-// Copy of same class in ServiceWorkerContainer.cpp
-class UndefinedValue {
-public:
-    typedef blink::WebGeofencingError WebType;
-    static V8UndefinedType take(ScriptPromiseResolver* resolver, WebType* value)
-    {
-        ASSERT(!value); // Anything passed here will be leaked.
-        return V8UndefinedType();
-    }
-
-    static void dispose(WebType* value)
-    {
-        ASSERT(!value); // Anything passed here will be leaked.
-    }
-
-private:
-    UndefinedValue();
-};
-
 class RegionArray {
 public:
     typedef blink::WebVector<blink::WebGeofencingRegion> WebType;
@@ -76,7 +57,7 @@ ScriptPromise Geofencing::registerRegion(ScriptState* scriptState, GeofencingReg
     RefPtr<ScriptPromiseResolver> resolver = ScriptPromiseResolver::create(scriptState);
     ScriptPromise promise = resolver->promise();
     // TODO(mek): somehow pass a reference to the current serviceworker to the provider.
-    provider->registerRegion(region->webRegion(), new CallbackPromiseAdapter<UndefinedValue, GeofencingError>(resolver));
+    provider->registerRegion(region->webRegion(), new CallbackPromiseAdapter<void, GeofencingError>(resolver));
     return promise;
 }
 
@@ -89,7 +70,7 @@ ScriptPromise Geofencing::unregisterRegion(ScriptState* scriptState, const Strin
     RefPtr<ScriptPromiseResolver> resolver = ScriptPromiseResolver::create(scriptState);
     ScriptPromise promise = resolver->promise();
     // TODO(mek): somehow pass a reference to the current serviceworker to the provider.
-    provider->unregisterRegion(regionId, new CallbackPromiseAdapter<UndefinedValue, GeofencingError>(resolver));
+    provider->unregisterRegion(regionId, new CallbackPromiseAdapter<void, GeofencingError>(resolver));
     return promise;
 }