Enforce range in SkPaint::setAlpha

This restores behavior from before SkColor4f (that was being enforced
via SkColorSetARGB).

Bug: skia:
Change-Id: I1f206366c96d20d87918117546de9bba08db28ad
Reviewed-on: https://skia-review.googlesource.com/151665
Auto-Submit: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
1 file changed