Revert "Add public API support for SkImageFilters::RuntimeShader"

This reverts commit ad9d774c1fd570c27c85559bc350a606042fd92c.

Reason for revert: Task Test-Debian10-Clang-NUC7i5BNK-GPU-IntelIris640-x86_64-Release-All-DDL3_TSAN has been failing since this CL landed.

Original change's description:
> Add public API support for SkImageFilters::RuntimeShader
>
> 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>

Change-Id: I0367a5c480df109c6116eb168792fe3c2fc58807
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/475644
Auto-Submit: Leandro Lovisolo <lovisolo@google.com>
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>
Reviewed-by: Derek Sollenberger <djsollen@google.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Leandro Lovisolo <lovisolo@google.com>
6 files changed