Remove GP from drawstate, revision of invariant output for GP

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/c6bc58eded89b0c0a36b8e20e193c200f297a0da

Review URL: https://codereview.chromium.org/791743003
diff --git a/src/gpu/effects/GrConvolutionEffect.h b/src/gpu/effects/GrConvolutionEffect.h
index 7fda369..1d0950b 100644
--- a/src/gpu/effects/GrConvolutionEffect.h
+++ b/src/gpu/effects/GrConvolutionEffect.h
@@ -99,7 +99,7 @@
     virtual void onComputeInvariantOutput(GrInvariantOutput* inout) const {
         // If the texture was opaque we could know that the output color if we knew the sum of the
         // kernel values.
-        inout->mulByUnknownColor();
+        inout->mulByUnknownFourComponents();
     }
 
     GR_DECLARE_FRAGMENT_PROCESSOR_TEST;