Revert of Lay groundwork for SkOpts. (patchset #3 id:40001 of https://codereview.chromium.org/1255193002/)

Reason for revert:
Chromium doesn't call SkGraphics::Init().  This setup won't work.

Original issue's description:
> Lay groundwork for SkOpts.
>
> This doesn't really do anything yet.  It's just the CPU detection code, skeleton new .cpp files, and a few little .gyp tweaks.
>
> BUG=skia:4117
>
> Committed: https://skia.googlesource.com/skia/+/ce2c5055cee5d5d3c9fc84c1b3eeed4b4d84a827

TBR=djsollen@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:4117

Review URL: https://codereview.chromium.org/1261743002
10 files changed