Flush TaskScheduler in ~ScopedTaskEnvironment and ~ScopedAsyncTaskScheduler.

base/test/scoped_task_environment.cc

Index: base/test/scoped_task_environment.cc
diff --git a/base/test/scoped_task_environment.cc b/base/test/scoped_task_environment.cc
index 8744b4a6b11427fe84c82bb7567708fff11b552c..33e6de03800a3e408cbb78841db0de6c63ce393a 100644
--- a/base/test/scoped_task_environment.cc
+++ b/base/test/scoped_task_environment.cc
@@ -32,6 +32,7 @@ ScopedTaskEnvironment::~ScopedTaskEnvironment() {
   RunLoop().RunUntilIdle();
 
   DCHECK_EQ(TaskScheduler::GetInstance(), task_scheduler_);
+  TaskScheduler::GetInstance()->FlushForTesting();

[gab, 2017/04/12 19:18:34]

Add a comment explaining why it's required.

[fdoray, 2017/04/12 19:38:05]

Done.

   TaskScheduler::GetInstance()->Shutdown();
   TaskScheduler::GetInstance()->JoinForTesting();
   TaskScheduler::SetInstance(nullptr);