Refactor 'in uniform' CPP code generation

Easily supports mapping ctypes to sksl types with templates that
specify how to send data to the GPU and how to track state changes.
The template logic and type mappings are defined in
SkSLCPPUniformCTypes.* while SkSLCPPCodeGenerator is updated to
utilize it.

It also updates the supported ctypes to properly generate code for
SkPoint, SkIPoint, SkIRect, and GrColor4f. The code generated for
'in uniforms' now also correctly supports conditional uniforms.


Bug: skia:
Change-Id: Ib7c0a873bdd68a966b6a00871f33102dfa2c432d
Reviewed-on: https://skia-review.googlesource.com/150129
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
32 files changed