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

dm/DM.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "CrashHandler.h"
 #include "DMJsonWriter.h"
 #include "DMSrcSink.h"
@@ skipping 1075 matching lines @@
     // CPU tests run on any thread.  GPU tests depend on --gpu_threading.
     SkTArray<Task> enclaves[kNumEnclaves];
     for (int j = 0; j < gSinks.count(); j++) {
         SkTArray<Task>& tasks = enclaves[gSinks[j]->enclave()];
         for (int i = 0; i < gSrcs.count(); i++) {
             tasks.push_back(Task(gSrcs[i], gSinks[j]));
         }
     }
 
     SkTaskGroup tg;
-    tg.batch([](int i){ run_test(&gThreadedTests[i]); }, gThreadedTests.count());
+    tg.batch(gThreadedTests.count(), [](int i){ run_test(&gThreadedTests[i]); });
     for (int i = 0; i < kNumEnclaves; i++) {
         SkTArray<Task>* currentEnclave = &enclaves[i];
         switch(i) {
             case kAnyThread_Enclave:
-                tg.batch([currentEnclave](int j) { Task::Run(&(*currentEnclave)[j]); }, currentEnclave->count());
+                tg.batch(currentEnclave->count(),
+                         [currentEnclave](int j) { Task::Run(&(*currentEnclave)[j]); });
                 break;
             case kGPU_Enclave:
                 tg.add([currentEnclave](){ run_enclave_and_gpu_tests(currentEnclave); });
                 break;
             default:
                 tg.add([currentEnclave](){ run_enclave(currentEnclave); });
                 break;
         }
     }
     tg.wait();
@@ skipping 111 matching lines @@
                                                            Reporter* reporter,
                                                            GrContextFactory* factory);
 } // namespace skiatest
 
 #if !defined(SK_BUILD_FOR_IOS)
 int main(int argc, char** argv) {
     SkCommandLineFlags::Parse(argc, argv);
     return dm_main();
 }
 #endif