Clean up Parser::doQuotes().

Yes, I'm a perfectionistic masochist.  But there are 1-2 extra levels of
indentation here that could go away.  Touch up some comments while
we're at it.

Change-Id: Iab2c2c8a565186eb7e7cf02ba6094f762a1b0a99
Merge "Clean up Parser::doQuotes()."