Add base::test::ScopedTaskEnvironment::RunUntilIdle().

base/test/scoped_task_environment_unittest.cc

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/test/scoped_task_environment.h"
+
+#include "base/bind.h"
+#include "base/synchronization/atomic_flag.h"
+#include "base/task_scheduler/post_task.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+namespace test {
+
+namespace {
+
+void VerifyRunUntilIdleDidNotReturnAndSetFlag(
+    AtomicFlag* run_until_idle_returned,
+    AtomicFlag* task_ran) {
+  EXPECT_FALSE(run_until_idle_returned->IsSet());
+  task_ran->Set();
+}
+
+}  // namespace
+
+TEST(ScopedTaskEnvironmentTest, RunUntilIdle) {
+  AtomicFlag run_until_idle_returned;
+  ScopedTaskEnvironment scoped_task_environment;
+
+  AtomicFlag first_main_thread_task_ran;
+  ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, BindOnce(&VerifyRunUntilIdleDidNotReturnAndSetFlag,
+                          Unretained(&run_until_idle_returned),
+                          Unretained(&first_main_thread_task_ran)));
+
+  AtomicFlag first_task_scheduler_task_ran;
+  PostTask(FROM_HERE, BindOnce(&VerifyRunUntilIdleDidNotReturnAndSetFlag,
+                               Unretained(&run_until_idle_returned),
+                               Unretained(&first_task_scheduler_task_ran)));
+
+  AtomicFlag second_task_scheduler_task_ran;
+  AtomicFlag second_main_thread_task_ran;
+  PostTaskAndReply(FROM_HERE,
+                   BindOnce(&VerifyRunUntilIdleDidNotReturnAndSetFlag,
+                            Unretained(&run_until_idle_returned),
+                            Unretained(&second_task_scheduler_task_ran)),
+                   BindOnce(&VerifyRunUntilIdleDidNotReturnAndSetFlag,
+                            Unretained(&run_until_idle_returned),
+                            Unretained(&second_main_thread_task_ran)));
+
+  scoped_task_environment.RunUntilIdle();
+  run_until_idle_returned.Set();
+
+  EXPECT_TRUE(first_main_thread_task_ran.IsSet());
+  EXPECT_TRUE(first_task_scheduler_task_ran.IsSet());
+  EXPECT_TRUE(second_task_scheduler_task_ran.IsSet());
+  EXPECT_TRUE(second_main_thread_task_ran.IsSet());
+}
+
+}  // namespace test
+}  // namespace base