Fix handling of MaskFilter matrices

1) extend GrFPArgs to track pre/post local matrices, add helpers for
   creating pre/post wrapper args

2) add a SkShaderBase helper (totalLocalMatrix) to centralize the LM
   sandwich logic.

3) update call sites to use the above

4) rename SkMatrixFilter::makeWithLocalMatrix -> makeWithMatrix, to
   disambiguate vs. SkShader::makeWithLocalMatrix.

BUG=skia:7744

Change-Id: Ib2b7b007e6924979b00649dde7c94ef4b34771f1
Reviewed-on: https://skia-review.googlesource.com/119330
Commit-Queue: Florin Malita <fmalita@chromium.org>
Reviewed-by: Brian Salomon <bsalomon@google.com>
21 files changed