fix bounds for BW lines, AA Hairlines

src/gpu/GrAAHairLinePathRenderer.cpp

Index: src/gpu/GrAAHairLinePathRenderer.cpp
diff --git a/src/gpu/GrAAHairLinePathRenderer.cpp b/src/gpu/GrAAHairLinePathRenderer.cpp
index f9b0c5a7ffca5f536c5207711ad58bd2c7491626..5b4540dc4a129faf4a3e23e1313ba95d4e11b9d1 100644
--- a/src/gpu/GrAAHairLinePathRenderer.cpp
+++ b/src/gpu/GrAAHairLinePathRenderer.cpp
@@ -731,6 +731,10 @@ private:
         // compute bounds
         fBounds = geometry.fPath.getBounds();
         geometry.fViewMatrix.mapRect(&fBounds);
+
+        // This is b.c. hairlines are notionally infinitely thin so without expansion
+        // two overlapping lines could be reordered even though they hit the same pixels.
+        fBounds.outset(0.5f, 0.5f);
     }
 
     bool onCombineIfPossible(GrBatch* t) override {