Revert "Remove lazy image color space hacks for gray"

This reverts commit a81c2be75adcc6ca63171d88df3c8bf2cb694ee7.

Reason for revert: Bad images on gold.

Original change's description:
> Remove lazy image color space hacks for gray
> 
> Change-Id: Idca6c0bb237d7973f84acbd2f0583cc8b6c6292c
> Reviewed-on: https://skia-review.googlesource.com/150241
> Reviewed-by: Mike Klein <mtklein@google.com>
> Commit-Queue: Brian Osman <brianosman@google.com>

TBR=mtklein@google.com,scroggo@google.com,brianosman@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: I08658c69eb7b0b9adfc36e73fbbd09ff1aad75f6
Reviewed-on: https://skia-review.googlesource.com/150464
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2 files changed