Refactoring MatchRanges and RuleRange.

TEST=no new tests, just refactoring.
BUG=172051

Review URL: https://codereview.chromium.org/214333003

git-svn-id: svn://svn.chromium.org/blink/trunk@170175 bbb929c8-8fbe-4397-9dbb-9b2b20218538