Support FileDescriptorWatcher in TaskScheduler.

base/task_scheduler/task_scheduler_impl.cc

Index: base/task_scheduler/task_scheduler_impl.cc
diff --git a/base/task_scheduler/task_scheduler_impl.cc b/base/task_scheduler/task_scheduler_impl.cc
index a3fc0d3830b99086093df55a4acab424195b921f..2ace2905f4c559ae37808fd09ca244a902a50c8c 100644
--- a/base/task_scheduler/task_scheduler_impl.cc
+++ b/base/task_scheduler/task_scheduler_impl.cc
@@ -13,6 +13,7 @@
 #include "base/task_scheduler/sequence_sort_key.h"
 #include "base/task_scheduler/task.h"
 #include "base/time/time.h"
+#include "build/build_config.h"
 
 namespace base {
 namespace internal {
@@ -53,11 +54,13 @@ scoped_refptr<TaskRunner> TaskSchedulerImpl::CreateTaskRunnerWithTraits(
 
 void TaskSchedulerImpl::Shutdown() {
   // TODO(fdoray): Increase the priority of BACKGROUND tasks blocking shutdown.
-  task_tracker_.Shutdown();
+  DCHECK(task_tracker_);
+  task_tracker_->Shutdown();
 }
 
 void TaskSchedulerImpl::FlushForTesting() {
-  task_tracker_.Flush();
+  DCHECK(task_tracker_);
+  task_tracker_->Flush();
 }
 
 void TaskSchedulerImpl::JoinForTesting() {
@@ -86,7 +89,7 @@ void TaskSchedulerImpl::Initialize(
 
   // Start the service thread.
   constexpr MessageLoop::Type kServiceThreadMessageLoopType =
-#if defined(OS_POSIX)
+#if defined(OS_POSIX) && !defined(OS_NACL_SFI)
       MessageLoop::TYPE_IO;
 #else
       MessageLoop::TYPE_DEFAULT;
@@ -95,6 +98,12 @@ void TaskSchedulerImpl::Initialize(
   CHECK(service_thread_.StartWithOptions(
       Thread::Options(kServiceThreadMessageLoopType, kDefaultStackSize)));
 
+  task_tracker_ = MakeUnique<TaskTracker>(
+#if defined(OS_POSIX) && !defined(OS_NACL_SFI)
+      static_cast<MessageLoopForIO*>(service_thread_.message_loop())
+#endif
+          );
+
   const SchedulerWorkerPoolImpl::ReEnqueueSequenceCallback
       re_enqueue_sequence_callback =
           Bind(&TaskSchedulerImpl::ReEnqueueSequenceCallback, Unretained(this));
@@ -102,7 +111,7 @@ void TaskSchedulerImpl::Initialize(
   // Instantiate the DelayedTaskManager. The service thread must be started
   // before its TaskRunner is available.
   delayed_task_manager_ =
-      base::MakeUnique<DelayedTaskManager>(service_thread_.task_runner());
+      MakeUnique<DelayedTaskManager>(service_thread_.task_runner());
 
   // Start worker pools.
   for (const auto& worker_pool_params : worker_pool_params_vector) {
@@ -110,7 +119,7 @@ void TaskSchedulerImpl::Initialize(
     // SchedulerWorkerPoolImpl::Create() is safe because a TaskSchedulerImpl
     // can't be deleted before all its worker pools have been joined.
     worker_pools_.push_back(SchedulerWorkerPoolImpl::Create(
-        worker_pool_params, re_enqueue_sequence_callback, &task_tracker_,
+        worker_pool_params, re_enqueue_sequence_callback, task_tracker_.get(),
         delayed_task_manager_.get()));
     CHECK(worker_pools_.back());
   }