Provide shipping address only to merchants that need it.

If the merchant provides NULL shipping options, the merchant needs a
shipping address to calculate shipping costs. The UI requires the user
to make an address selection and passes that information to the
merchant.

If the merchant provides non-NULL shipping options, the merchant does
not need shipping address to calculate shipping costs. The UI selects
the default shipping address, but does not send it to the merchant until
the user clicks "Pay".

BUG=587995

Review-Url: https://codereview.chromium.org/1942653002
Cr-Commit-Position: refs/heads/master@{#391004}
1 file changed