Introduce SchedulerSingleThreadTaskRunnerManager

base/task_scheduler/task_scheduler_impl_unittest.cc

 // Copyright 2016 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/task_scheduler/task_scheduler_impl.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <utility>
@@ skipping 304 matching lines @@
       scheduler_->GetMaxConcurrentTasksWithTraitsDeprecated(
           TaskTraits().WithPriority(TaskPriority::USER_VISIBLE).MayBlock()));
   EXPECT_EQ(4, scheduler_->GetMaxConcurrentTasksWithTraitsDeprecated(
                    TaskTraits().WithPriority(TaskPriority::USER_BLOCKING)));
   EXPECT_EQ(
       12,
       scheduler_->GetMaxConcurrentTasksWithTraitsDeprecated(
           TaskTraits().WithPriority(TaskPriority::USER_BLOCKING).MayBlock()));
 }
 
+// Verify that the RunsTasksOnCurrentThread() method of a Sequenced TaskRunner
+// returns false when called from a task that isn't part of the sequence. Note:

[gab, 2017/02/21 21:39:50]

"Note:" ?

[robliao, 2017/02/22 01:04:19]

Removed. (It's no longer needed)

+TEST_F(TaskSchedulerImplTest, SequencedRunsTasksOnCurrentThread) {
+  auto task_runner =
+      scheduler_->CreateSingleThreadTaskRunnerWithTraits(TaskTraits());
+  auto sequenced_task_runner =
+      scheduler_->CreateSequencedTaskRunnerWithTraits(TaskTraits());
+
+  WaitableEvent task_ran(WaitableEvent::ResetPolicy::MANUAL,
+                         WaitableEvent::InitialState::NOT_SIGNALED);
+  task_runner->PostTask(
+      FROM_HERE,
+      Bind(
+          [](scoped_refptr<TaskRunner> sequenced_task_runner,
+             WaitableEvent* task_ran) {
+            EXPECT_FALSE(sequenced_task_runner->RunsTasksOnCurrentThread());
+            task_ran->Signal();
+          },
+          sequenced_task_runner, Unretained(&task_ran)));
+  task_ran.Wait();

[gab, 2017/02/21 21:39:50]

Also test the other way around?

And drop
TaskSchedulerSingleThreadTaskRunnerManagerTest.SequencedRunsTasksOnCurrentThread
because it's redundant?

[robliao, 2017/02/22 01:04:19]

Removed redundant test and added reverse.

+}
+
 }  // namespace internal
 }  // namespace base