TaskScheduler: Don't use a callback to post a task from TaskTracker.

base/task_scheduler/scheduler_worker_thread_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/scheduler_worker_thread.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <vector>
@@ skipping 112 matching lines @@
       EXPECT_LE(num_get_work_, max_get_work_);
 
       // Check if a Sequence should be returned.
       if (num_sequences_to_create_ == 0)
         return nullptr;
       --num_sequences_to_create_;
     }
 
     // Create a Sequence that contains one Task.
     scoped_refptr<Sequence> sequence(new Sequence);
-    task_tracker_.PostTask(
-        Bind(IgnoreResult(&Sequence::PushTask), Unretained(sequence.get())),
-        WrapUnique(new Task(
-            FROM_HERE, Bind(&TaskSchedulerWorkerThreadTest::RunTaskCallback,
-                            Unretained(this)),
-            TaskTraits())));
+    std::unique_ptr<Task> task(new Task(
+        FROM_HERE,
+        Bind(&TaskSchedulerWorkerThreadTest::RunTaskCallback, Unretained(this)),
+        TaskTraits()));
+    EXPECT_TRUE(task_tracker_.WillPostTask(task.get()));
+    sequence->PushTask(std::move(task));
 
     {
       // Add the Sequence to the vector of created Sequences.
       AutoSchedulerLock auto_lock(lock_);
       created_sequences_.push_back(sequence);
     }
 
     return sequence;
   }
 
@@ skipping 86 matching lines @@
     // GetWork().
     worker_thread_->WakeUp();
     WaitForAllSequencesToRun();
     WaitForNumGetWork(expected_num_get_work);
   }
 }
 
 }  // namespace
 }  // namespace internal
 }  // namespace base