More sample count cleanup:

rename getSampleCount -> getRenderTargetSampleCount because it will return
0 when a config is not renderable but *is* supported as a texture format.
(Old name kept around until Chrome stops calling it)

Add virtual GrCaps::maxRenderTargetSampleCount(GrPixelConfig).

Devirtualize isConfigRenderable() and implement as maxRTSC != 0. Separate implementation for version with bool withMSAA param to be removed after Flutter is updated to no longer call.

Consolidate various file static GrSurfaceDesc validators fns into GrCaps::validateSurfaceDesc().


Bug: skia:
Change-Id: Ie30a291aa027e910df3bd90fac8518ccdb39e53f
Reviewed-on: https://skia-review.googlesource.com/102141
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
32 files changed