[css-flexbox] "used flex basis of 'auto'" needs s/auto/content/

The Flexbox ED section 9.2 step 3 has text about "auto" in the used
flex-basis, in cases B,C,D,E. I believe each of those mentions really
wants to say "content.

Here's the chunk that I believe needs changing:
 # B. If the flex item has [...]
 #   a used flex basis of 'auto', and
 #   [...]
 # C. If the used flex basis is 'auto' [...]
 # D. Otherwise, if the used flex basis is 'auto' [...]
 # E. Otherwise, lay out the item into the available space
 #    using its used flex basis [...] treating [...] auto
 #    as max-content.

Link: http://dev.w3.org/csswg/css-flexbox/#algo-main-item

I think in each of those cases, we really want to say "content" instead
of "auto". With the new "flex-basis: content" keyword, I believe it
should actually be *impossible* to have a used 'flex-basis' of auto.
The current "flex-basis" spec text says that
"flex-basis:auto;width:auto" produces a used value of "content", not
"auto" -- here's the relevant quote for that:
 # The auto keyword retrieves the value of the main size property.
 # If that value is also auto, then the used value is 'content'.
http://dev.w3.org/csswg/css-flexbox/#auto

Thanks,
~Daniel