Reland "Separate texture creation from uploading in GrGpu subclasses."

This is a reland of a7398246cb80746994df430261ed72822a1f60ba

TBR:egdaniel@google.com

Original change's description:
> Separate texture creation from uploading in GrGpu subclasses.
>
> GrGpu base class still allows creation with initial data, but separated
> at subclass level into create and then write pixels.
>
> GrGpu handles determining which levels need clearing and GrGpu
> subclasses take a mask and clear levels with mask bit set.
>
> GrGLGpu uses three pronged clear strategy:
> glClearTexImage() if supported, glClear() if format is FBO bindable, and
> lastly glTexSubImage2D with zero'ed buffer.
>
> Change-Id: I65fb1e60eed8f9d0896d686d3baeb10b57ff8f39
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/236676
> Commit-Queue: Brian Salomon <bsalomon@google.com>
> Reviewed-by: Greg Daniel <egdaniel@google.com>

Change-Id: I54cda3b6a4b017a94ef1f50bb3748c45a24d8936
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/240558
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
21 files changed