Re-land of skslc switch support

This reverts commit 7d975fc200bbbea991ec4c04c08f3a5ea7b847af.

BUG=skia:

Change-Id: I57521f7a291a35cfed58d623ea4f8da29582d2c5
Reviewed-on: https://skia-review.googlesource.com/8993
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
19 files changed