Move RenderBoxClipper to core/paint/

Only used/referenced from paint code. Straight-forward code movement, while
renaming RenderBoxClipper -> BoxClipper.

BUG=412088

Review URL: https://codereview.chromium.org/732093002

git-svn-id: svn://svn.chromium.org/blink/trunk@185460 bbb929c8-8fbe-4397-9dbb-9b2b20218538
6 files changed
tree: 6870a6fdbf8619ffd1d7bc1e9f3e3b22450c916c
  1. third_party/