Reland "remove third_party/etc1"

This is a reland of 9d7a73527a6df7d3523e93a6a1f964df08b94510.

Original change's description:
> remove third_party/etc1
> 
> Nothing seems to reference it.
> 
> Change-Id: Ib009a7dc33d31439b11588758015a07485f56eaa
> Reviewed-on: https://skia-review.googlesource.com/99861
> Reviewed-by: Mike Klein <mtklein@chromium.org>
> Commit-Queue: Mike Klein <mtklein@chromium.org>

Change-Id: I3a6428074896c7b3c80cb23db61f70d7cb0c785f
Reviewed-on: https://skia-review.googlesource.com/108460
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>
6 files changed