Improved optional command handling in SkParsePath::FromSVGString()

Repeating command letters are optional in SVG path data strings:
https://www.w3.org/TR/SVG/paths.html#PathData

FromSVGString() already supports this feature, but only checks for
scalars prefixes == (digit | '-' | '+').

A decimal point is also a valid scalar prefix though, so it should be
included in the test.

R=caryclark@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2339813003

Review-Url: https://codereview.chromium.org/2339813003
2 files changed