Merge Element::offsetParentForBindings() into offsetParent()

This split was introduced with a fix for "offsetParent should never
return nodes in user agent Shadow DOM to script" in 2013:
https://trac.webkit.org/changeset/146037

SpatialNavigations's rectToAbsoluteCoordinates was the only internal use
of Element::offsetParent(). Rewrite that in a way that preserves the
existing behavior.

Review URL: https://codereview.chromium.org/994903003

git-svn-id: svn://svn.chromium.org/blink/trunk@191902 bbb929c8-8fbe-4397-9dbb-9b2b20218538
5 files changed
tree: 9b5229184d7c266f5c0372a8d266717679499def
  1. third_party/