Stub out Skia AVX and HSW opts.

This is hopefully temporary while we mull better options.

BUG=666707

Review-Url: https://codereview.chromium.org/2512093003
Cr-Commit-Position: refs/heads/master@{#433407}
(cherry picked from commit 2ea76e2274404af7e53cc4bb5d212b22856ee455)

Review URL: https://codereview.chromium.org/2519083004 .

Cr-Commit-Position: refs/branch-heads/2924@{#47}
Cr-Branched-From: 3a87aecc31cd1ffe751dd72c04e5a96a1fc8108a-refs/heads/master@{#433059}
3 files changed