Remove unnecessary TextureSampler comparison in GrTextureDomainEffect.

The base class already performs this comparison.

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4960

Change-Id: Ic2a46e05f05ba36b291c05e324aa29b4aad15c23
Reviewed-on: https://skia-review.googlesource.com/4960
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/effects/GrTextureDomain.cpp b/src/gpu/effects/GrTextureDomain.cpp
index 4418730..4d163b8 100644
--- a/src/gpu/effects/GrTextureDomain.cpp
+++ b/src/gpu/effects/GrTextureDomain.cpp
@@ -242,8 +242,7 @@
 
 bool GrTextureDomainEffect::onIsEqual(const GrFragmentProcessor& sBase) const {
     const GrTextureDomainEffect& s = sBase.cast<GrTextureDomainEffect>();
-    return this->fTextureDomain == s.fTextureDomain &&
-           s.textureSampler(0) == this->textureSampler(0);
+    return this->fTextureDomain == s.fTextureDomain;
 }
 
 void GrTextureDomainEffect::onComputeInvariantOutput(GrInvariantOutput* inout) const {