[canvaskit] Make SkCanvas.drawColor/clear take SkColor4f

CanvasKit converts 4 floats to an int, just to have it be
converted back into 4 floats when it goes into the paint.

Change-Id: I93cf1c596283b83cc9452fb205b7000ceed09bb9
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/293538
Commit-Queue: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Mike Reed <reed@google.com>
4 files changed