Cherry pick: Don't allow iteration through non-finite points.

Original CL:

    Don't allow iteration through non-finite points.

    Added a unit test too.

    BUG=chromium:756563

    Change-Id: Ic77a89b4a98d1a553877af9807a3d3bdcd077bb9
    Reviewed-on: https://skia-review.googlesource.com/44420
    Commit-Queue: Mike Klein <mtklein@chromium.org>
    Reviewed-by: Mike Reed <reed@google.com>

This cherry picks that to m62 minus its additional unit test, which
had some awkward formatting-based merge conflicts.  Only the change
to SkPathRef.cpp is important here.

Change-Id: Ic3e1fa4244a921064d0c0b8a8afafd72af39df4d
Reviewed-on: https://skia-review.googlesource.com/48043
Reviewed-by: Mike Klein <mtklein@chromium.org>
2 files changed