Remove input-color modulation from GrGLLightingEffect.

This fragment processor is not accessible to the outside world; it's
only accessible via `SkLightingImageFilterInternal::drawRect`, which
creates its own GrPaint and does not set a custom paint color. The input
color is always default white, so the modulation step is wasted effort.

Change-Id: Ia6c18edab069947ec80b372c1d0728b5ed6ffc98
Bug: skia:10217
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/305725
Commit-Queue: John Stiles <johnstiles@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
1 file changed