Fix Ganesh analytic blurred rect draws

This CL does two things:
 It fixes the SkBlurMaskFilterImpl::directFilterRRectMaskGPU draw path to explicitly handle rects
 It fixes the SkGpuDevice::drawTextureProducerImpl draw path to provide the correct (src & device space) inputs to directFilterRRectMaskGPU.

How this was working before was that GrRRectBlurEffect::Make would reject rect-rrects and the code would fallback to
GrBlurUtils::drawPathWithMaskFilter which mapped the rect-rrect into device space correctly (of course,
the rect-ness of the path was removed at that point so it was going through the slow path).

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2268583002

Review-Url: https://codereview.chromium.org/2268583002
2 files changed