Generate getters/setters/mappings for text-justify.

Currently, the text-justify property is a 'storage_only' field,
so it has no generated public getters/setters. This patch changes it to
a 'keyword' field so that its getters/setters can be generated as well.

TextJustify is in platform/text, so we can't generate the enum itself.
However, we can also generate the CSSValueID <-> TextJustify mappings.

Diff of generated files:
https://gist.github.com/darrnshn/3defc5f6001a21f272ab77a06a4520f7/revisions

Bug: 628043
Change-Id: I158f503cf747957434bc6a0580ec5922480d154e
Reviewed-on: https://chromium-review.googlesource.com/527842
Reviewed-by: Alan Cutter <alancutter@chromium.org>
Commit-Queue: Darren Shen <shend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#477938}
3 files changed