Revert "More fixes for distance field paths"

Revert "More fixes for distance field paths"

This reverts commit d081ff314f07104adacaadc3d0f8f13dc741f016.

Reason for revert: Failing unit tests.

Original change's description:
> More fixes for distance field paths
>
> Disables use of SDFs for very small paths (because of blurring) and
> adds a border of 1 pixel in device space to handle antialiasing.
>
> BUG=chromium:677889
>
> Change-Id: I81e49477c943d41523fd836e55abd696a985491f
> Reviewed-on: https://skia-review.googlesource.com/6832
> Commit-Queue: Jim Van Verth <jvanverth@google.com>
> Reviewed-by: Brian Salomon <bsalomon@google.com>
>

TBR=jvanverth@google.com,bsalomon@google.com,robertphillips@google.com,reviews@skia.org
BUG=chromium:677889
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: I4a6a698fa2e9e58c1c98a5a89f54bed724527951
Reviewed-on: https://skia-review.googlesource.com/6890
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>