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 c5d8ae11269f66fdd3496e37650c38604f0b7b9b..3508727e7760f96e603aeb15e65d79580ba3a3bb 100644
--- a/src/gpu/GrAAHairLinePathRenderer.cpp
+++ b/src/gpu/GrAAHairLinePathRenderer.cpp
@@ -730,6 +730,10 @@ 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 {