If we swap its arguments, SkTaskGroup::batch() _is_ sk_parallel_for.

tests/SkpSkGrTest.cpp

Index: tests/SkpSkGrTest.cpp
diff --git a/tests/SkpSkGrTest.cpp b/tests/SkpSkGrTest.cpp
index 98c54e032cddb9e6941c846d8a513bfe43819b47..241395a7533c09e80d76541295e6b4d11c5df6b6 100644
--- a/tests/SkpSkGrTest.cpp
+++ b/tests/SkpSkGrTest.cpp
@@ -171,7 +171,7 @@ SkpSkGrThreadedTestRunner::~SkpSkGrThreadedTestRunner() {
 void SkpSkGrThreadedTestRunner::render() {
     // TODO: we don't really need to be using SkRunnables here anymore.
     // We can just write the code we'd run right in the for loop.
-    sk_parallel_for(fRunnables.count(), [&](int i) {
+    SkTaskGroup().batch(fRunnables.count(), [&](int i) {
         fRunnables[i]->run();
     });
 }