Adding functions to the window_list_provider for accessing the activities window list

athena/resource_manager/resource_manager_impl.cc

Index: athena/resource_manager/resource_manager_impl.cc
diff --git a/athena/resource_manager/resource_manager_impl.cc b/athena/resource_manager/resource_manager_impl.cc
index 42351a0a6121fc75105487f56eb478a1218b9a2b..d5c4782153315c1d4c34e72491bfe2bfb4f5beec 100644
--- a/athena/resource_manager/resource_manager_impl.cc
+++ b/athena/resource_manager/resource_manager_impl.cc
@@ -195,6 +195,11 @@ void ResourceManagerImpl::OnSplitViewModeExit() {
 void ResourceManagerImpl::OnWindowStackingChanged(aura::Window* window) {
   // TODO(skuhne): This needs to be changed to some WindowListProvider observer
   // if we decouple window order from activity order.
+  activity_order_changed_ = true;
+  if (pause_) {
+    queued_command_ = true;
+    return;
+  }
 
   // No need to do anything while being in overview mode.
   if (in_overview_mode_)