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

public/platform/WebGeofencingProvider.h

Index: public/platform/WebGeofencingProvider.h
diff --git a/public/platform/WebGeofencingProvider.h b/public/platform/WebGeofencingProvider.h
index 830896e9705704bf949dc370cabdefcecd523d5b..9db470cff1d88fab35b8a3fa4869ccf02aa1c7b2 100644
--- a/public/platform/WebGeofencingProvider.h
+++ b/public/platform/WebGeofencingProvider.h
@@ -14,21 +14,19 @@ struct WebGeofencingError;
 class WebGeofencingRegion;
 class WebString;
 
-typedef WebCallbacks<WebGeofencingError, WebGeofencingError> WebGeofencingCallbacks;
+typedef WebCallbacks<void, WebGeofencingError> WebGeofencingCallbacks;
 typedef WebCallbacks<WebVector<WebGeofencingRegion>, WebGeofencingError> WebGeofencingRegionsCallbacks;
 
 class WebGeofencingProvider {
 public:
     virtual ~WebGeofencingProvider() { }
 
-    // Registers a region. The provider must always pass null to onSuccess.
+    // Registers a region.
     // Ownership of the WebGeofencingCallbacks is transferred to the client.
-    // FIXME: cleanup the callback type to not have a success type.
     virtual void registerRegion(const WebGeofencingRegion&, WebGeofencingCallbacks*) = 0;
 
-    // Unregisters a region. The provider must always pass null to onSuccess.
+    // Unregisters a region.
     // Ownership of the WebGeofencingCallbacks is transferred to the client.
-    // FIXME: cleanup the callback type to not have a success type.
     virtual void unregisterRegion(const WebString& regionId, WebGeofencingCallbacks*) = 0;
 
     // Returns all the currently registered regions.