Remove outdated TODO in SequencedWorkerPool::Inner::IsRunningSequenceOnCurrentThread().

base/threading/sequenced_worker_pool.cc

Index: base/threading/sequenced_worker_pool.cc
diff --git a/base/threading/sequenced_worker_pool.cc b/base/threading/sequenced_worker_pool.cc
index d8884dbf38fa996938037b1264827e9f728fd8c0..334d65a44e8d295db7e9df7c4ef78fcabb589c3b 100644
--- a/base/threading/sequenced_worker_pool.cc
+++ b/base/threading/sequenced_worker_pool.cc
@@ -879,13 +879,12 @@ bool SequencedWorkerPool::Inner::RunsTasksOnCurrentThread() const {
 
 bool SequencedWorkerPool::Inner::IsRunningSequenceOnCurrentThread(
     SequenceToken sequence_token) const {
+  DCHECK(sequence_token.IsValid());

[fdoray, 2016/09/15 15:57:13]

This is always called from PoolSequencedTaskRunner::RunsTasksOnCurrentThread
with a valid sequence token (hmm... unless the PoolSequencedTaskRunner was
created with an invalid SequenceToken, which doesn't seem like a valid thing to
do...)

+
   AutoLock lock(lock_);
+
   if (subtle::NoBarrier_Load(&g_all_pools_state) ==
       AllPoolsState::REDIRECTED_TO_TASK_SCHEDULER) {
-    // TODO(gab): This currently only verifies that the current thread is a

[danakj, 2016/09/15 18:31:09]

Isn't SequencedWorkerPool::Inner::RunsTasksOnCurrentThread still just making a
task runner and checking if it uses the current thread? I'm kinda confused

[fdoray, 2016/09/15 18:39:23]

|sequenced_task_runner_map_| contains TaskScheduler TaskRunners. Line 892 calls
SchedulerSequencedTaskRunner::RunsTasksOnCurrentThread which does exactly what
we want (i.e. tell us if the current task is part of the the sequence associated
with |sequence_token|) since https://codereview.chromium.org/2340793002/

[danakj, 2016/09/15 18:41:26]

Thanks for the context! LGTM

-    // thread on which a task bound to |sequence_token| *could* run, but it
-    // doesn't verify that the current is *currently running* a task bound to
-    // |sequence_token|.
     const auto sequenced_task_runner_it =
         sequenced_task_runner_map_.find(sequence_token.id_);
     return sequenced_task_runner_it != sequenced_task_runner_map_.end() &&
@@ -893,9 +892,7 @@ bool SequencedWorkerPool::Inner::IsRunningSequenceOnCurrentThread(
   } else {
     ThreadMap::const_iterator found =
         threads_.find(PlatformThread::CurrentId());
-    if (found == threads_.end())
-      return false;
-    return found->second->is_processing_task() &&
+    return found != threads_.end() && found->second->is_processing_task() &&
            sequence_token.Equals(found->second->task_sequence_token());
   }
 }