Check for bounds intersection when batching MSAAPathOps

Change-Id: Ic4f1e13728b1137ffdc94dab077ec065619a0221
Reviewed-on: https://skia-review.googlesource.com/8883
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>

src/gpu/ops/GrMSAAPathRenderer.cpp

@@ -456,6 +456,10 @@ private:
             return false;
         }
 
+        if (this->bounds().intersects(that->bounds())) {
+            return false;
+        }
+
         if (!fViewMatrix.cheapEqualTo(that->fViewMatrix)) {
             return false;
         }