Google Drive XBlock - Fake PR for review purposes, do not merge!

@martynjames Created this PR for the review. 

Btw for the future, it's easier to create this when the first commit is empty. Also, if we want to review a series of PRs at once instead of individual PRs, it would be easier to merge the individual PRs in a branch which isn't master, and then create a PR from that branch into master when it's ready -- this way we don't need "fake" PRs at all, they represent the actual review workflow.
OK, I see the property up above is probably an index into this array. This seems a little dangerous because if - in code - the ordering of the views with respect to its index changes, it's going to do non-intuitive things as the authored value is persisted in the content database. Might it be better to use an enumerated value. I believe there's some examples that I'll try to find.