enable color4f doc examples

fiddle has picked up the SkPaint::(get)(set)Color4f
include change, so the doc examples are ready to
check in.

NOTRY=true
R=brianosman@google.com

Docs-Preview: https://skia.org/?cl=151370
Bug: skia:6898
Change-Id: I2c7ad3ce892ea6c8fde524df8e48a3c5713e2ba9
Reviewed-on: https://skia-review.googlesource.com/151370
Reviewed-by: Cary Clark <caryclark@skia.org>
Commit-Queue: Cary Clark <caryclark@skia.org>
Auto-Submit: Cary Clark <caryclark@skia.org>
3 files changed