Use WebFilterOperations for reference filters 

This uses WebFilterOperations to pass reference filters
from Blink to chromium. With this change, all accelerated
filters are set using WebLayer::setFilters, so this also
removes the now-unused WebLayer::setFilter.

BUG=181613

Review URL: https://codereview.chromium.org/23522020

git-svn-id: svn://svn.chromium.org/blink/trunk@158770 bbb929c8-8fbe-4397-9dbb-9b2b20218538