Allow implicit conversion from GrSamplerState::Filter to GrSamplerState

constexprify GrSamplerState

pass/return GrSamplerState by value (it's 3 bytes).

Remove unused function from GrTexturePriv

Change-Id: Iffecd941500acf5653f01cc88b42ff1d45678b54
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/263346
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/GrPrimitiveProcessor.cpp b/src/gpu/GrPrimitiveProcessor.cpp
index 270a14c..ade7e4d 100644
--- a/src/gpu/GrPrimitiveProcessor.cpp
+++ b/src/gpu/GrPrimitiveProcessor.cpp
@@ -60,13 +60,13 @@
     return requestedFilter;
 }
 
-GrPrimitiveProcessor::TextureSampler::TextureSampler(const GrSamplerState& samplerState,
+GrPrimitiveProcessor::TextureSampler::TextureSampler(GrSamplerState samplerState,
                                                      const GrBackendFormat& backendFormat,
                                                      const GrSwizzle& swizzle) {
     this->reset(samplerState, backendFormat, swizzle);
 }
 
-void GrPrimitiveProcessor::TextureSampler::reset(const GrSamplerState& samplerState,
+void GrPrimitiveProcessor::TextureSampler::reset(GrSamplerState samplerState,
                                                  const GrBackendFormat& backendFormat,
                                                  const GrSwizzle& swizzle) {
     fSamplerState = samplerState;
@@ -75,4 +75,3 @@
     fSwizzle = swizzle;
     fIsInitialized = true;
 }
-