GrGLSLGeometryProcessor produces a map  FP -> varying coords.

Removes the FPCoordTransformHandler that required code to iterate
FPs in the same order as GLSLGP when accessing varyings stored in
and array.

Bug: skia:12198
Change-Id: Ie906b56491bafd76778b241e5ec95b0b253364b6
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/428197
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
8 files changed