Reland: mus: Enable system modal windows

components/mus/ws/window_manager_state.cc

Index: components/mus/ws/window_manager_state.cc
diff --git a/components/mus/ws/window_manager_state.cc b/components/mus/ws/window_manager_state.cc
index 681a52345687cd9536817f4c5dbb4ef4d18303b6..71e69c4d4434ef16c794bd7931f443be8da3b0b6 100644
--- a/components/mus/ws/window_manager_state.cc
+++ b/components/mus/ws/window_manager_state.cc
@@ -127,23 +127,16 @@ bool WindowManagerState::SetCapture(ServerWindow* window,
 
 void WindowManagerState::ReleaseCaptureBlockedByModalWindow(
     const ServerWindow* modal_window) {
-  if (!capture_window() || !modal_window->is_modal() ||
-      !modal_window->IsDrawn())
-    return;
-
-  if (modal_window->transient_parent() &&
-      !modal_window->transient_parent()->Contains(capture_window())) {
-    return;
-  }
-
-  SetCapture(nullptr, false);
+  event_dispatcher_.ReleaseCaptureBlockedByModalWindow(modal_window);
 }
 
 void WindowManagerState::ReleaseCaptureBlockedByAnyModalWindow() {
-  if (!capture_window() || !capture_window()->IsBlockedByModalWindow())
-    return;
+  event_dispatcher_.ReleaseCaptureBlockedByAnyModalWindow();
+}
 
-  SetCapture(nullptr, false);
+void WindowManagerState::AddSystemModalWindow(ServerWindow* window) {
+  DCHECK(!window->transient_parent());
+  event_dispatcher_.AddSystemModalWindow(window);
 }
 
 mojom::DisplayPtr WindowManagerState::ToMojomDisplay() const {