TaskScheduler: Add TaskRunnerHandle support to TaskScheduler tasks

base/task_scheduler/test_task_factory.h

Index: base/task_scheduler/test_task_factory.h
diff --git a/base/task_scheduler/test_task_factory.h b/base/task_scheduler/test_task_factory.h
index 9102c7c59b9ef6116b588bee792693ede59a41e0..9ed15a1bac20ab683cb3488bffc1c80bf94ef697 100644
--- a/base/task_scheduler/test_task_factory.h
+++ b/base/task_scheduler/test_task_factory.h
@@ -29,10 +29,12 @@ namespace test {
 // expected. Generates a test failure when:
 // - The RunsTasksOnCurrentThread() method of the TaskRunner returns false on a
 //   thread on which a Task is run.
+// - The TaskRunnerHandles set in the context of the task don't match what's
+//   expected for the tested ExecutionMode.
 // - The ExecutionMode of the TaskRunner is SEQUENCED or SINGLE_THREADED and
 //   Tasks don't run in posting order.
-// - The ExecutionMode of the TaskRunner is SINGLE_THREADED and Tasks don't
-//   run on the same thread.
+// - The ExecutionMode of the TaskRunner is SINGLE_THREADED and Tasks don't run
+//   on the same thread.
 // - A Task runs more than once.
 class TestTaskFactory {
  public: