Consider conical shader opaque if it covers entire plane.

src/effects/gradients/SkTwoPointConicalGradient.cpp

Index: src/effects/gradients/SkTwoPointConicalGradient.cpp
diff --git a/src/effects/gradients/SkTwoPointConicalGradient.cpp b/src/effects/gradients/SkTwoPointConicalGradient.cpp
index 37b49f0d475a22c9eecfb2027649e32e8b475587..7cb094391a60a46a1b3c6bae4f7610666216385d 100644
--- a/src/effects/gradients/SkTwoPointConicalGradient.cpp
+++ b/src/effects/gradients/SkTwoPointConicalGradient.cpp
@@ -74,6 +74,8 @@ void TwoPtRadial::init(const SkPoint& center0, SkScalar rad0,
     fA = sqr(fDCenterX) + sqr(fDCenterY) - sqr(fDRadius);
     fRadius2 = sqr(fRadius);
     fRDR = fRadius * fDRadius;
+
+    fConeFillsPlane = rad0 != rad1 && SkMaxScalar(rad0, rad1) > SkPoint::Distance(center0, center1);
 }
 
 void TwoPtRadial::setup(SkScalar fx, SkScalar fy, SkScalar dfx, SkScalar dfy) {
@@ -189,10 +191,7 @@ SkTwoPointConicalGradient::SkTwoPointConicalGradient(
 }
 
 bool SkTwoPointConicalGradient::isOpaque() const {
-    // Because areas outside the cone are left untouched, we cannot treat the
-    // shader as opaque even if the gradient itself is opaque.
-    // TODO(junov): Compute whether the cone fills the plane crbug.com/222380
-    return false;
+    return INHERITED::isOpaque() && this->fRec.fConeFillsPlane;
 }
 
 void SkTwoPointConicalGradient::shadeSpan(int x, int y, SkPMColor* dstCParam,