Reland: [skjson] Unescape strings

Reviewed-on: https://skia-review.googlesource.com/c/167240
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>
Change-Id: Icfa1b335f19423422f2fe6fb592b40f7b72b16eb
TBR=
Reviewed-on: https://skia-review.googlesource.com/c/168265
Reviewed-by: Florin Malita <fmalita@chromium.org>
2 files changed