Extract AD policy scheduler into separate class

components/policy/core/common/BUILD.gn

Index: components/policy/core/common/BUILD.gn
diff --git a/components/policy/core/common/BUILD.gn b/components/policy/core/common/BUILD.gn
index 17217b1ad8741015d0bc8313ae8ed4612de3b605..a07adeb16640117ab58d1c2e9730ae48cbfb2eea 100644
--- a/components/policy/core/common/BUILD.gn
+++ b/components/policy/core/common/BUILD.gn
@@ -157,6 +157,7 @@ source_set("internal") {
       "ntdsapi.lib",
     ]
   }
+
   # Compile on Linux for fuzzer and since code is reused on Chrome OS.
   if (is_win || is_linux) {
     sources += [
@@ -188,6 +189,8 @@ source_set("internal") {
   }
   if (is_chromeos) {
     sources += [
+      "policy_scheduler.cc",
+      "policy_scheduler.h",
       "proxy_policy_provider.cc",
       "proxy_policy_provider.h",
     ]
@@ -289,6 +292,7 @@ source_set("unit_tests") {
     "policy_loader_mac_unittest.cc",
     "policy_loader_win_unittest.cc",
     "policy_map_unittest.cc",
+    "policy_scheduler_unittest.cc",
     "policy_service_impl_unittest.cc",
     "policy_statistics_collector_unittest.cc",
     "remote_commands/remote_commands_queue_unittest.cc",