Bad encoding in title

Now that we don't buffer the document when looking for the
encoding in a <meta>, it's possible that we'll process the
<title> element before we process the <meta> element. In
that case, we'll have used the wrong encoding to decode the
document's title.

When that situation arises, this CL causes us to go back
and "re-decode" the title element using the new encoding.
This CL isn't the prettiest, but it lets us avoid buffering
the document waiting for a charset in a meta tag.

R=eseidel
BUG=258483

Review URL: https://chromiumcodereview.appspot.com/20016002

git-svn-id: svn://svn.chromium.org/blink/trunk@154775 bbb929c8-8fbe-4397-9dbb-9b2b20218538