Add the COM STA Task Runner

base/task_scheduler/scheduler_single_thread_task_runner_manager.h

Index: base/task_scheduler/scheduler_single_thread_task_runner_manager.h
diff --git a/base/task_scheduler/scheduler_single_thread_task_runner_manager.h b/base/task_scheduler/scheduler_single_thread_task_runner_manager.h
index 6fbad4bb1d0e7ef5a64a843a65c4118c48899b63..1f8bcff3a9ae925d98f648c6ce29a8413eeae685 100644
--- a/base/task_scheduler/scheduler_single_thread_task_runner_manager.h
+++ b/base/task_scheduler/scheduler_single_thread_task_runner_manager.h
@@ -15,6 +15,7 @@
 #include "base/task_scheduler/scheduler_lock.h"
 #include "base/task_scheduler/scheduler_worker_pool_params.h"
 #include "base/task_scheduler/task_scheduler.h"
+#include "build/build_config.h"
 
 namespace base {
 
@@ -40,13 +41,26 @@ class BASE_EXPORT SchedulerSingleThreadTaskRunnerManager final {
   scoped_refptr<SingleThreadTaskRunner> CreateSingleThreadTaskRunnerWithTraits(
       const TaskTraits& traits);
 
+#if defined(OS_WIN)
+  scoped_refptr<SingleThreadTaskRunner> CreateCOMSTATaskRunnerWithTraits(
+      const TaskTraits& traits);
+#endif  // defined(OS_WIN)
+
   void JoinForTesting();
 
  private:
   class SchedulerSingleThreadTaskRunner;
 
+  enum class DelegateType {
+    DEFAULT,
+#if defined(OS_WIN)
+    COM_STA,
+#endif  // defined(OS_WIN)
+  };
+
   SchedulerWorker* CreateAndRegisterSchedulerWorker(
-      const SchedulerWorkerPoolParams& params);
+      const SchedulerWorkerPoolParams& params,
+      DelegateType delegate_type);
 
   void UnregisterSchedulerWorker(SchedulerWorker* worker);