NOT INTENDED FOR LANDING: A promises demo

components/scheduler/BUILD.gn

Index: components/scheduler/BUILD.gn
diff --git a/components/scheduler/BUILD.gn b/components/scheduler/BUILD.gn
index 489bbb5c0b74f399cfb7602d287805cf1bbaf063..e51849a07d46b41dc3259ddaa4e2241a8eb16eb3 100644
--- a/components/scheduler/BUILD.gn
+++ b/components/scheduler/BUILD.gn
@@ -55,6 +55,14 @@ component("scheduler") {
     "child/worker_scheduler.h",
     "child/worker_scheduler_impl.cc",
     "child/worker_scheduler_impl.h",
+    "promises/promise.cc",
+    "promises/promise.h",
+    "promises/promise_executor.cc",
+    "promises/promise_executor.h",
+    "promises/single_thread_promise_executor.cc",
+    "promises/single_thread_promise_executor.h",
+    "promises/thread_pool_promise_executor.cc",
+    "promises/thread_pool_promise_executor.h",
     "renderer/auto_advancing_virtual_time_domain.cc",
     "renderer/auto_advancing_virtual_time_domain.h",
     "renderer/deadline_task_runner.cc",
@@ -135,6 +143,9 @@ source_set("unit_tests") {
     "child/scheduler_tqm_delegate_impl_unittest.cc",
     "child/webthread_impl_for_worker_scheduler_unittest.cc",
     "child/worker_scheduler_impl_unittest.cc",
+    "promises/promise_unittest.cc",
+    "promises/single_thread_promise_executor_unittest.cc",
+    "promises/thread_pool_promise_executor_unittest.cc",
     "renderer/auto_advancing_virtual_time_domain_unittest.cc",
     "renderer/deadline_task_runner_unittest.cc",
     "renderer/idle_time_estimator_unittest.cc",