This new image filter constructor enables SkRuntimeEffects to be
used as shaders within the ImageFilter DAG. The shader is created
lazily using the SkRuntimeShaderBuilder enabling the resulting
shader to consume the previous stage of the ImageFilter graph.
Change-Id: I5d6917e34a8e5fdd053399f15a1e2cc7409e686f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/470459
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Derek Sollenberger <djsollen@google.com>
ad9d774c1f