queueReplacement is always called to replace the node that's currently
being visited in the traverser. The currently visited node can be
fetched automatically from the traversal path so it can be removed
from parameters of queueReplacement.

BUG=angleproject:2100
TEST=angle_unittests

Change-Id: I62ab6d1cd9c0d2b4c260af9f7c85bc156fb3f349
Reviewed-on: https://chromium-review.googlesource.com/562336Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>