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

base/test/launcher/unit_test_launcher.cc

Index: base/test/launcher/unit_test_launcher.cc
diff --git a/base/test/launcher/unit_test_launcher.cc b/base/test/launcher/unit_test_launcher.cc
index c9f0eb0afb139f02094dcb62408f747379fdda67..44c440fb76f4be9355a783bcfcc7b09def078bcc 100644
--- a/base/test/launcher/unit_test_launcher.cc
+++ b/base/test/launcher/unit_test_launcher.cc
@@ -439,9 +439,9 @@ void SerialGTestCallback(
   DeleteFile(callback_state.output_file.DirName(), true);
 
   ThreadTaskRunnerHandle::Get()->PostTask(
-      FROM_HERE, Bind(&RunUnitTestsSerially, callback_state.test_launcher,
-                      callback_state.platform_delegate, test_names,
-                      callback_state.launch_flags));
+      FROM_HERE, BindOnce(&RunUnitTestsSerially, callback_state.test_launcher,
+                          callback_state.platform_delegate, test_names,
+                          callback_state.launch_flags));
 }
 
 }  // namespace
@@ -636,8 +636,9 @@ size_t UnitTestLauncherDelegate::RetryTests(
     const std::vector<std::string>& test_names) {
   ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE,
-      Bind(&RunUnitTestsSerially, test_launcher, platform_delegate_, test_names,
-           use_job_objects_ ? TestLauncher::USE_JOB_OBJECTS : 0));
+      BindOnce(&RunUnitTestsSerially, test_launcher, platform_delegate_,
+               test_names,
+               use_job_objects_ ? TestLauncher::USE_JOB_OBJECTS : 0));
   return test_names.size();
 }