Redirect the MessageLoop's task runner to the renderer scheduler

components/scheduler/child/task_queue_manager_unittest.cc

 // Copyright 2014 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 "components/scheduler/child/task_queue_manager.h"
 
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "base/threading/thread.h"
@@ skipping 104 matching lines @@
   enum class SelectorType {
     Automatic,
     Explicit,
   };
 
   void Initialize(size_t num_queues, SelectorType type) {
     now_src_.reset(new base::SimpleTestTickClock());
     now_src_->Advance(base::TimeDelta::FromMicroseconds(1000));
     test_task_runner_ = make_scoped_refptr(
         new cc::OrderedSimpleTaskRunner(now_src_.get(), false));
+    main_task_runner_ =
+        NestableTaskRunnerForTest::Create(test_task_runner_.get());
     selector_ = make_scoped_ptr(createSelectorForTest(type));
-    manager_ = make_scoped_ptr(new TaskQueueManager(
-        num_queues, NestableTaskRunnerForTest::Create(test_task_runner_.get()),
-        selector_.get(), "test.scheduler", "test.scheduler.debug"));
+    manager_ = make_scoped_ptr(
+        new TaskQueueManager(num_queues, main_task_runner_, selector_.get(),
+                             "test.scheduler", "test.scheduler.debug"));
     manager_->SetTimeSourceForTesting(
         make_scoped_ptr(new TestTimeSource(now_src_.get())));
 
     EXPECT_EQ(num_queues, selector_->work_queues().size());
   }
 
   void InitializeWithRealMessageLoop(size_t num_queues, SelectorType type) {
     message_loop_.reset(new base::MessageLoop());
     selector_ = make_scoped_ptr(createSelectorForTest(type));
     manager_ = make_scoped_ptr(new TaskQueueManager(
@@ skipping 31 matching lines @@
         &TaskQueueManager::PumpPolicyToString);
   }
 
   static void CheckAllWakeupPolicyToString() {
     CallForEachEnumValue<TaskQueueManager::WakeupPolicy>(
         TaskQueueManager::WakeupPolicy::FIRST_WAKEUP_POLICY,
         TaskQueueManager::WakeupPolicy::WAKEUP_POLICY_COUNT,
         &TaskQueueManager::WakeupPolicyToString);
   }
 
+  scoped_ptr<base::MessageLoop> message_loop_;
   scoped_ptr<base::SimpleTestTickClock> now_src_;
+  scoped_refptr<NestableTaskRunnerForTest> main_task_runner_;
   scoped_refptr<cc::OrderedSimpleTaskRunner> test_task_runner_;
   scoped_ptr<SelectorForTest> selector_;
   scoped_ptr<TaskQueueManager> manager_;
-  scoped_ptr<base::MessageLoop> message_loop_;
 };
 
 void PostFromNestedRunloop(base::MessageLoop* message_loop,
                            base::SingleThreadTaskRunner* runner,
                            std::vector<std::pair<base::Closure, bool>>* tasks) {
   base::MessageLoop::ScopedNestableTaskAllower allow(message_loop);
   for (std::pair<base::Closure, bool>& pair : *tasks) {
     if (pair.second) {
       runner->PostTask(FROM_HERE, pair.first);
     } else {
@@ skipping 1040 matching lines @@
   EXPECT_EQ(TaskQueueManager::QueueState::HAS_WORK,
             manager_->GetQueueState(1));
 
   test_task_runner_->RunUntilIdle();
   EXPECT_EQ(TaskQueueManager::QueueState::EMPTY,
             manager_->GetQueueState(0));
   EXPECT_EQ(TaskQueueManager::QueueState::EMPTY,
             manager_->GetQueueState(1));
 }
 
+TEST_F(TaskQueueManagerTest, DefaultTaskRunnerRegistration) {
+  Initialize(1u, SelectorType::Automatic);
+  EXPECT_EQ(main_task_runner_->default_task_runner(),
+            manager_->TaskRunnerForQueue(0));
+}
+

[alex clarke (OOO till 29th), 2015/07/08 13:30:53]

Can we have a test to ensure the original task runner is restored when the TQM
goes away?

[Sami, 2015/07/08 18:45:07]

Done.

[alex clarke (OOO till 29th), 2015/07/10 15:21:11]

Not seeing the test, does it still make sense to have it? (presumably not here
though).

[Sami, 2015/07/10 15:35:12]

That one's now in
components/scheduler/child/scheduler_task_runner_delegate_impl_unittest.cc.

 }  // namespace scheduler