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

tests/SkSharedMutexTest.cpp

Index: tests/SkSharedMutexTest.cpp
diff --git a/tests/SkSharedMutexTest.cpp b/tests/SkSharedMutexTest.cpp
index bdf072b6b75cc471f5f8692f49292d39464db1d8..845889174b44c673ac93bd812cdcae08ac18283c 100644
--- a/tests/SkSharedMutexTest.cpp
+++ b/tests/SkSharedMutexTest.cpp
@@ -28,7 +28,7 @@ DEF_TEST(SkSharedMutexMultiThreaded, r) {
     for (int i = 0; i < kSharedSize; ++i) {
         shared[i] = 0;
     }
-    sk_parallel_for(8, [&](int threadIndex) {
+    SkTaskGroup().batch(8, [&](int threadIndex) {
         if (threadIndex % 4 != 0) {
             for (int c = 0; c < 100000; ++c) {
                 sm.acquireShared();