Make GrFragmentProcessor auto-compare coord xforms.

src/effects/gradients/SkGradientShader.cpp

Index: src/effects/gradients/SkGradientShader.cpp
diff --git a/src/effects/gradients/SkGradientShader.cpp b/src/effects/gradients/SkGradientShader.cpp
index b297b14fb051c8b40a0924a8ba64c36b9366c3da..f131d72f237abfb3409bbc01c5fa78d6f1ce2d13 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -1205,8 +1205,7 @@ bool GrGradientEffect::onIsEqual(const GrFragmentProcessor& processor) const {
         return fTextureAccess.getTexture() == s.fTextureAccess.getTexture()  &&
             fTextureAccess.getParams().getTileModeX() ==
                 s.fTextureAccess.getParams().getTileModeX() &&
-            this->useAtlas() == s.useAtlas() &&
-            fCoordTransform.getMatrix().cheapEqualTo(s.fCoordTransform.getMatrix());
+            this->useAtlas() == s.useAtlas();
     }
 
     return false;