This is a reland of 45889d1269
Original change's description:
> Remove code to push pixmaps to backend textures from GrGpu classes
>
> Replace GrGpu::updateBackendTexture with narrower method that clears
> a backend texture.
>
> Creation of data for a solid color compressed texture is lifted up to
> GrDirectContext and goes through updateCompressedBackendTexture.
>
> Bug: skia:11786
> Change-Id: I1d617623df5e65686f30e57c361a64f78d77f7bd
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/392836
> Reviewed-by: Jim Van Verth <jvanverth@google.com>
> Reviewed-by: Greg Daniel <egdaniel@google.com>
> Commit-Queue: Brian Salomon <bsalomon@google.com>
Bug: skia:11786
Change-Id: Ibf85794a33e68acb17f0fb704f6815cd6460b3f2
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/396098
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
71283238d1