Asynchronously load a content filter given its identifier.
The filter must have been previously stored using webkit.user_content_filter_store.UserContentFilterStore.save.
When the operation is finished, callback will be invoked, which then can use webkit.user_content_filter_store.UserContentFilterStore.loadFinish to obtain the resulting filter.
a filter identifier
a #GCancellable or null to ignore
a #GAsyncReadyCallback to call when the load is completed
Asynchronously load a content filter given its identifier.
The filter must have been previously stored using webkit.user_content_filter_store.UserContentFilterStore.save.
When the operation is finished, callback will be invoked, which then can use webkit.user_content_filter_store.UserContentFilterStore.loadFinish to obtain the resulting filter.