Add Support to Get a COM STA Task Runner from the Task Scheduler API

base/task_scheduler/task_scheduler_impl_unittest.cc

Index: base/task_scheduler/task_scheduler_impl_unittest.cc
diff --git a/base/task_scheduler/task_scheduler_impl_unittest.cc b/base/task_scheduler/task_scheduler_impl_unittest.cc
index bacedb7cf98747e75dc9f8987fe25b8e5027b026..1489baebe4f958f5d12477ac2dc9c19e6ed41376 100644
--- a/base/task_scheduler/task_scheduler_impl_unittest.cc
+++ b/base/task_scheduler/task_scheduler_impl_unittest.cc
@@ -28,6 +28,10 @@
 #include "base/time/time.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+#if defined(OS_WIN)
+#include <objbase.h>
+#endif  // defined(OS_WIN)
+
 namespace base {
 namespace internal {
 
@@ -366,5 +370,29 @@ TEST_F(TaskSchedulerImplTest, SingleThreadRunsTasksOnCurrentThread) {
   task_ran.Wait();
 }
 
+#if defined(OS_WIN)
+TEST_F(TaskSchedulerImplTest, COMSTATaskRunnersRunWithCOMSTA) {
+  auto com_sta_task_runner =
+      scheduler_->CreateCOMSTATaskRunnerWithTraits(TaskTraits());
+
+  WaitableEvent task_ran(WaitableEvent::ResetPolicy::MANUAL,
+                         WaitableEvent::InitialState::NOT_SIGNALED);
+  com_sta_task_runner->PostTask(
+      FROM_HERE,
+      Bind(
+          [](scoped_refptr<TaskRunner> single_thread_task_runner,
+             WaitableEvent* task_ran) {
+            HRESULT hr = CoInitializeEx(nullptr, COINIT_MULTITHREADED);
+            if (SUCCEEDED(hr)) {
+              ADD_FAILURE() << "COM STA was not initialized on this thread";
+              CoUninitialize();
+            }
+            task_ran->Signal();
+          },
+          com_sta_task_runner, Unretained(&task_ran)));
+  task_ran.Wait();
+}
+#endif  // defined(OS_WIN)
+
 }  // namespace internal
 }  // namespace base