Support FileDescriptorWatcher in TaskScheduler.

base/task_scheduler/scheduler_worker_stack_unittest.cc

Index: base/task_scheduler/scheduler_worker_stack_unittest.cc
diff --git a/base/task_scheduler/scheduler_worker_stack_unittest.cc b/base/task_scheduler/scheduler_worker_stack_unittest.cc
index 022e1961de6f9c02d67ace0a911c2dce9ebc6e16..5a8142b74037add21ec9bebcc8ee1cb2b664c333 100644
--- a/base/task_scheduler/scheduler_worker_stack_unittest.cc
+++ b/base/task_scheduler/scheduler_worker_stack_unittest.cc
@@ -7,12 +7,14 @@
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/ref_counted.h"
+#include "base/message_loop/message_loop.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 "build/build_config.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
@@ -44,6 +46,13 @@ class MockSchedulerWorkerDelegate : public SchedulerWorker::Delegate {
 
 class TaskSchedulerWorkerStackTest : public testing::Test {
  protected:
+  TaskSchedulerWorkerStackTest()
+#if defined(OS_POSIX) && !defined(OS_NACL_SFI)
+      : task_tracker_(&watch_file_descriptor_message_loop_)
+#endif
+  {
+  }
+
   void SetUp() override {
     worker_a_ = SchedulerWorker::Create(
         ThreadPriority::NORMAL,
@@ -73,7 +82,12 @@ class TaskSchedulerWorkerStackTest : public testing::Test {
   std::unique_ptr<SchedulerWorker> worker_c_;
 
  private:
+#if defined(OS_POSIX) && !defined(OS_NACL_SFI)
+  MessageLoopForIO watch_file_descriptor_message_loop_;
+#endif
   TaskTracker task_tracker_;
+
+  DISALLOW_COPY_AND_ASSIGN(TaskSchedulerWorkerStackTest);
 };
 
 }  // namespace