Remove the nested heap API.

This isn't currently used and it isn't compatible with the new design, we'll reimplement this if needed.

BUG=
[email protected]

Review URL: https://codereview.appspot.com/128460044

git-svn-id: http://sawbuck.googlecode.com/svn/trunk@2265 15e8cca8-e42c-11de-a347-f34a4f72eb7d
9 files changed