Move LengthSizes border-*-radius out of BorderData

In StyleSurroundData, the border longhand properties are stored in a
single BorderData. This makes it difficult to generate because the
generator assumes that properties don't share storage.

This patch splits the LenthSize objects maintaining the border-*-radius
into individual properties stored directly on the surround group

Generated files diff here:


Cr-Commit-Position: refs/heads/master@{#468907}
9 files changed