TaskScheduler: Record TaskScheduler.NumTasksBeforeDetach.* from OnDetach().

base/task_scheduler/scheduler_worker_stack_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_stack.h"
 
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/task_scheduler/scheduler_worker.h"
 #include "base/task_scheduler/sequence.h"
 #include "base/task_scheduler/task_tracker.h"
 #include "base/test/gtest_util.h"
 #include "base/threading/platform_thread.h"
 #include "base/time/time.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 namespace internal {
 
 namespace {
 
 class MockSchedulerWorkerDelegate : public SchedulerWorker::Delegate {
  public:
-  void OnMainEntry(SchedulerWorker* worker,
-                   const TimeDelta& detach_duration) override {}
+  void OnMainEntry(SchedulerWorker* worker) override {}
   scoped_refptr<Sequence> GetWork(SchedulerWorker* worker) override {
     return nullptr;
   }
   void DidRunTaskWithPriority(TaskPriority task_priority,
                               const TimeDelta& task_latency) override {
     ADD_FAILURE() << "Unexpected call to DidRunTaskWithPriority()";
   }
   void ReEnqueueSequence(scoped_refptr<Sequence> sequence) override {
     ADD_FAILURE() << "Unexpected call to ReEnqueueSequence()";
   }
   TimeDelta GetSleepTimeout() override {
     return TimeDelta::Max();
   }
   bool CanDetach(SchedulerWorker* worker) override {
     return false;
   }
+  void OnDetach() override { ADD_FAILURE() << "Unexpected call to OnDetach()"; }
 };
 
 class TaskSchedulerWorkerStackTest : public testing::Test {
  protected:
   void SetUp() override {
     worker_a_ = SchedulerWorker::Create(
         ThreadPriority::NORMAL,
         WrapUnique(new MockSchedulerWorkerDelegate), &task_tracker_,
         SchedulerWorker::InitialState::ALIVE);
     ASSERT_TRUE(worker_a_);
@@ skipping 198 matching lines @@
 
 // Verify that Push() DCHECKs when a value is inserted twice.
 TEST_F(TaskSchedulerWorkerStackTest, PushTwice) {
   SchedulerWorkerStack stack;
   stack.Push(worker_a_.get());
   EXPECT_DCHECK_DEATH({ stack.Push(worker_a_.get()); });
 }
 
 }  // namespace internal
 }  // namespace base