[ThreadPool]: Use const ref in RemoveTaskSource.

Change-Id: I3b4c51879cef4b97c777715f5d190cb33decbd77
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1834897
Commit-Queue: Etienne Pierre-Doray <etiennep@chromium.org>
Reviewed-by: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#706570}

base/task/thread_pool/priority_queue.cc

@@ -139,20 +139,18 @@ RegisteredTaskSource PriorityQueue::PopTaskSource() {
 }
 
 RegisteredTaskSource PriorityQueue::RemoveTaskSource(
-    scoped_refptr<TaskSource> task_source) {
-  DCHECK(task_source);
-
+    const TaskSource& task_source) {
   if (IsEmpty())
     return nullptr;
 
-  const HeapHandle heap_handle = task_source->heap_handle();
+  const HeapHandle heap_handle = task_source.heap_handle();
   if (!heap_handle.IsValid())
     return nullptr;
 
   TaskSourceAndSortKey& task_source_and_sort_key =
       const_cast<PriorityQueue::TaskSourceAndSortKey&>(
           container_.at(heap_handle));
-  DCHECK_EQ(task_source_and_sort_key.task_source().get(), task_source);
+  DCHECK_EQ(task_source_and_sort_key.task_source().get(), &task_source);
   RegisteredTaskSource registered_task_source =
       task_source_and_sort_key.take_task_source();
 

base/task/thread_pool/priority_queue.h

@@ -49,7 +49,7 @@ class BASE_EXPORT PriorityQueue {
   // RegisteredTaskSource which evaluates to true if successful, or false if
   // |task_source| is not currently in the PriorityQueue or the PriorityQueue is
   // empty.
-  RegisteredTaskSource RemoveTaskSource(scoped_refptr<TaskSource> task_source);
+  RegisteredTaskSource RemoveTaskSource(const TaskSource& task_source);
 
   // Updates the sort key of the TaskSource in |transaction| to
   // match its current traits. No-ops if the TaskSource is not in the

base/task/thread_pool/priority_queue_unittest.cc

@@ -144,34 +144,34 @@ TEST_F(PriorityQueueWithSequencesTest, RemoveSequence) {
 
   // Remove |sequence_a| from the PriorityQueue. |sequence_b| is still the
   // sequence with the highest priority.
-  EXPECT_TRUE(pq.RemoveTaskSource(sequence_a).Unregister());
+  EXPECT_TRUE(pq.RemoveTaskSource(*sequence_a).Unregister());
   EXPECT_EQ(sort_key_b, pq.PeekSortKey());
   ExpectNumSequences(1U, 0U, 2U);
 
   // RemoveTaskSource() should return false if called on a sequence not in the
   // PriorityQueue.
-  EXPECT_FALSE(pq.RemoveTaskSource(sequence_a).Unregister());
+  EXPECT_FALSE(pq.RemoveTaskSource(*sequence_a).Unregister());
   ExpectNumSequences(1U, 0U, 2U);
 
   // Remove |sequence_b| from the PriorityQueue. |sequence_c| becomes the
   // sequence with the highest priority.
-  EXPECT_TRUE(pq.RemoveTaskSource(sequence_b).Unregister());
+  EXPECT_TRUE(pq.RemoveTaskSource(*sequence_b).Unregister());
   EXPECT_EQ(sort_key_c, pq.PeekSortKey());
   ExpectNumSequences(1U, 0U, 1U);
 
   // Remove |sequence_d| from the PriorityQueue. |sequence_c| is still the
   // sequence with the highest priority.
-  EXPECT_TRUE(pq.RemoveTaskSource(sequence_d).Unregister());
+  EXPECT_TRUE(pq.RemoveTaskSource(*sequence_d).Unregister());
   EXPECT_EQ(sort_key_c, pq.PeekSortKey());
   ExpectNumSequences(0U, 0U, 1U);
 
   // Remove |sequence_c| from the PriorityQueue, making it empty.
-  EXPECT_TRUE(pq.RemoveTaskSource(sequence_c).Unregister());
+  EXPECT_TRUE(pq.RemoveTaskSource(*sequence_c).Unregister());
   EXPECT_TRUE(pq.IsEmpty());
   ExpectNumSequences(0U, 0U, 0U);
 
   // Return false if RemoveTaskSource() is called on an empty PriorityQueue.
-  EXPECT_FALSE(pq.RemoveTaskSource(sequence_c).Unregister());
+  EXPECT_FALSE(pq.RemoveTaskSource(*sequence_c).Unregister());
   ExpectNumSequences(0U, 0U, 0U);
 }
 

base/task/thread_pool/test_utils.cc

@@ -241,7 +241,7 @@ bool MockPooledTaskRunnerDelegate::EnqueueJobTaskSource(
 
 void MockPooledTaskRunnerDelegate::RemoveJobTaskSource(
     scoped_refptr<JobTaskSource> task_source) {
-  thread_group_->RemoveTaskSource(std::move(task_source));
+  thread_group_->RemoveTaskSource(*task_source);
 }
 
 bool MockPooledTaskRunnerDelegate::IsRunningPoolWithTraits(

base/task/thread_pool/thread_group.cc

@@ -139,9 +139,9 @@ ThreadGroup::GetNumAdditionalWorkersForForegroundTaskSourcesLockRequired()
 }
 
 RegisteredTaskSource ThreadGroup::RemoveTaskSource(
-    scoped_refptr<TaskSource> task_source) {
+    const TaskSource& task_source) {
   CheckedAutoLock auto_lock(lock_);
-  return priority_queue_.RemoveTaskSource(std::move(task_source));
+  return priority_queue_.RemoveTaskSource(task_source);
 }
 
 void ThreadGroup::ReEnqueueTaskSourceLockRequired(

base/task/thread_pool/thread_group.h

@@ -65,7 +65,7 @@ class BASE_EXPORT ThreadGroup {
   // RegisteredTaskSource that evaluats to true if successful, or false if
   // |task_source| is not currently in |priority_queue_|, such as when a worker
   // is running a task from it.
-  RegisteredTaskSource RemoveTaskSource(scoped_refptr<TaskSource> task_source);
+  RegisteredTaskSource RemoveTaskSource(const TaskSource& task_source);
 
   // Updates the position of the TaskSource in |transaction| in this
   // ThreadGroup's PriorityQueue based on the TaskSource's current traits.

base/task/thread_pool/thread_pool_impl.cc

@@ -431,7 +431,7 @@ void ThreadPoolImpl::RemoveJobTaskSource(
   auto transaction = task_source->BeginTransaction();
   ThreadGroup* const current_thread_group =
       GetThreadGroupForTraits(transaction.traits());
-  current_thread_group->RemoveTaskSource(std::move(task_source));
+  current_thread_group->RemoveTaskSource(*task_source);
 }
 
 bool ThreadPoolImpl::IsRunningPoolWithTraits(const TaskTraits& traits) const {
@@ -466,7 +466,7 @@ void ThreadPoolImpl::UpdatePriority(scoped_refptr<TaskSource> task_source,
     // |task_source| is changing thread groups; remove it from its current
     // thread group and reenqueue it.
     auto registered_task_source =
-        current_thread_group->RemoveTaskSource(task_source);
+        current_thread_group->RemoveTaskSource(*task_source);
     if (registered_task_source) {
       DCHECK(task_source);
       new_thread_group->PushTaskSourceAndWakeUpWorkers(