Revert of Make WindowState::CanMinimize() take into account WidgetDelegate::CanMinimize()

ash/wm/window_state.cc

Index: ash/wm/window_state.cc
diff --git a/ash/wm/window_state.cc b/ash/wm/window_state.cc
index 827fa1aff3f958514676b7687b7699bc5718f4a3..e95dc4060222015b22b6c1f0da4b5486fd5b6e00 100644
--- a/ash/wm/window_state.cc
+++ b/ash/wm/window_state.cc
@@ -153,7 +153,15 @@
 }
 
 bool WindowState::CanMinimize() const {
-  return window()->GetProperty(aura::client::kCanMinimizeKey);
+  RootWindowController* controller = RootWindowController::ForWindow(window_);
+  if (!controller)
+    return false;
+  aura::Window* lockscreen =
+      controller->GetContainer(kShellWindowId_LockScreenContainersContainer);
+  if (lockscreen->Contains(window_))
+    return false;
+
+  return true;
 }
 
 bool WindowState::CanResize() const {