It turns out the Cleanup() method in JsModalDialog is not

      needed. The check in it was reversed, causing it to never
do anything, except in the case where the delegate had been
deleted, in which case it would crash.

The thing it was trying to do is already being done elsewhere
in the case of OnAccept() and OnCancel(). That just leaves
OnClose().

There are other things in here that really need cleanup, but
I will do those separately.

BUG=63732
TEST=See bug

Review URL: http://codereview.chromium.org/5548001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@68447 0039d316-1c4b-4281-b951-d872f2087c98