Use Ash's ShelfWindowWatcher for app panel windows.

chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.cc

Index: chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.cc
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.cc b/chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.cc
index 70111f5b02b7542f35913398746e103d5e1fb5fb..257cbf124b8d3512ffb09a4da4aca3a2be964300 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.cc
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_controller_impl.cc
@@ -449,17 +449,15 @@ void ChromeLauncherControllerImpl::Launch(ash::ShelfID id, int event_flags) {
 }
 
 void ChromeLauncherControllerImpl::Close(ash::ShelfID id) {
-  LauncherItemController* controller = GetLauncherItemController(id);
-  if (!controller)
+  ash::ShelfItemDelegate* delegate = model_->GetShelfItemDelegate(id);
+  if (!delegate)
     return;  // May happen if menu closed.
-  controller->Close();
+  delegate->Close();
 }
 
 bool ChromeLauncherControllerImpl::IsOpen(ash::ShelfID id) {
-  LauncherItemController* controller = GetLauncherItemController(id);
-  if (!controller)
-    return false;
-  return controller->IsOpen();
+  ash::ShelfItemDelegate* delegate = model_->GetShelfItemDelegate(id);
+  return delegate && delegate->IsOpen();
 }
 
 bool ChromeLauncherControllerImpl::IsPlatformApp(ash::ShelfID id) {