We are going to implement online documentation in CDT
So we need to have a parser which parses wiki markup format.

BUG=391593

Review URL: https://codereview.chromium.org/430153002

git-svn-id: svn://svn.chromium.org/blink/trunk@179458 bbb929c8-8fbe-4397-9dbb-9b2b20218538