bd5a07bf1b
Similar to the change that refactors ChangeNotes out, I created a superclass, AbstractChangeUpdate, for use by both ChangeUpdate and the new Update class I will be writing for the purpose of draft comments. I extracted all common variables and methods that I thought generically should be part of an "update" of this kind. However, I left some out (see commit()) because they depended on functions that I thought aren't generic enough to be part of a generic update (see storeCommentsInNotes()). Finally, there was one method in ChangeUpdate that I refactored out to CommentsInNotesUtil because I knew that it will be needed there. I changed that method a bit because the old implementation depended on the fact that we were going to just be adding comments to the list of preexisting comments. However, with drafts, we will be adding and deleting, so I changed that method to force the caller to have already made all modifications to the list, so that the method just writes the list it is given to a note and writes that note to the NoteMap. Change-Id: I0229e895e34c4ddd728b461ac64e3b3be936032d