GitLab

An implementation of the intro data source. This data source is used to get the
intros for the APIs as well as construct the table of contents entries.

BUG=131095

Review URL: https://chromiumcodereview.appspot.com/10750017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@145818 0039d316-1c4b-4281-b951-d872f2087c98