[node] Allow GC in spite of reference loops through the request method

The following produces a reference cycle:

var map = new mbgl.Map({
    request: function () { ... }
});

map has a reference to the request function, which has a reference to
its closure, which has a reference to map.

Storing a the map options in an internal field, rather than a Persistent,
allows V8 to collect the reference cycle when none of its members have
other references.

0 files changed, 0 insertions, 0 deletions