Revert of Remove now-redundant SkPathOps enum. (patchset #1 id:1 of https://coderevie...

Revert of Remove now-redundant SkPathOps enum. (patchset #1 id:1 of https://codereview.chromium.org/1051113005/)

Reason for revert:
Android is still using this. See https://android-build.storage.googleapis.com/builds/git_master-skia-linux-razor-userdebug/1836783/4c2968b94c5f4b238ff5ba61111bf867ea872fd8dce930612f376711883419b8/logs/build_error.log?GoogleAccessId=701025073339-mqn0q2nvir9iurm6q5d00tdv7blbgvjr%40developer.gserviceaccount.com&Signature=ATvg9ZvwZGFDDVb%2B1Ue2WHVGaCCL1hAD7QjXeZv2gBT08I3JaKLcseUhV5K2G%2F%2BWUnsnSgNNjzjBnBLmnPbK9Uu8NC%2B%2F5J0dU3sKD8TU9dvMtkQhFQSp2x5t5Xxf5mczi2EPps%2FwoPHqTKQqrMgqStySzw206W1%2Fc135RrdrgYg%3D&Expires=1428415459

Original issue's description:
> Remove now-redundant SkPathOps enum.
>
> R=caryclark,reed
> BUG=473772
>
> Committed: https://skia.googlesource.com/skia/+/143244e27d95255807d8fa505ce0affef96d1fc8

TBR=caryclark@google.com,reed@google.com,schenney@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=473772

Review URL: https://codereview.chromium.org/1068873002