Use new retain() method to set up window context.

This makes our usage of sk_cf_obj consistent with Chrome.

Bug: skia:8243
Change-Id: I159339577a0e8595e7cdd47ffb9ab0653269e108
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/218973
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
1 file changed