Create floating-point square root path for 16b mirrored radial gradients (6x-16x speedup).  Create specialized dy=0 path for clamped radial gradients (25% speedup).  Make 16b radial gradient proc signature similar to 32b, passing in SkScalar instead of SkFixed and/or SkFloat.
Create floating-point square root path for 16b mirrored radial gradients
(6x-16x speedup).  Create specialized dy=0 path for clamped radial gradients
(25% speedup).  Make 16b radial gradient proc signature similar to 32b,
passing in SkScalar instead of SkFixed and/or SkFloat.



csulmone/skia,csulmone/skia,csulmone/skia,csulmone/skia