Fix latent bug in fragmentProcessorHasCoordsParam.

Previously, if you passed in a GrFragmentProcessor which didn't
exist in the map, you would get `false` indicating that the
coordinate parameter had been lifted, and an extra entry would be
inadvertently added to the FPCoordsMap.

In practice, I don't think this actually gets called with
unexpected GrFragmentProcessors so we wouldn't have run into
any issues.

Change-Id: I1ace289ada313be326d88feea56dcd333e3c2953
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/761597
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
2 files changed