Rewrite base::Bind into base::BindOnce on trivial cases in base

base/trace_event/trace_category_unittest.cc

Index: base/trace_event/trace_category_unittest.cc
diff --git a/base/trace_event/trace_category_unittest.cc b/base/trace_event/trace_category_unittest.cc
index a33924f4ffecd1cdaa520d232117b8775ca993f7..25f37ca73982fa328e6b8d41c25626352ea52a6d 100644
--- a/base/trace_event/trace_category_unittest.cc
+++ b/base/trace_event/trace_category_unittest.cc
@@ -130,7 +130,7 @@ TEST_F(TraceCategoryTest, ThreadRaces) {
                            WaitableEvent::InitialState::NOT_SIGNALED);
   for (int i = 0; i < kNumThreads; i++) {
     threads[i]->task_runner()->PostTask(
-        FROM_HERE, Bind(&TestRaceThreadMain, Unretained(&sync_event)));
+        FROM_HERE, BindOnce(&TestRaceThreadMain, Unretained(&sync_event)));
   }
   sync_event.Signal();
   for (int i = 0; i < kNumThreads; i++)