mash: Convert OnWindowInputEventAck to use an enum for handled status

components/mus/ws/window_tree_unittest.cc

Index: components/mus/ws/window_tree_unittest.cc
diff --git a/components/mus/ws/window_tree_unittest.cc b/components/mus/ws/window_tree_unittest.cc
index e89343bf1ff20c60bce8b34b8ca5494449cb8fd4..f5bd32129697c1ef2e2524b599d698e0e46f1982 100644
--- a/components/mus/ws/window_tree_unittest.cc
+++ b/components/mus/ws/window_tree_unittest.cc
@@ -127,8 +127,10 @@ class WindowTreeTest : public testing::Test {
 
   void AckPreviousEvent() {
     WindowManagerStateTestApi test_api(display_->GetActiveWindowManagerState());
-    while (test_api.tree_awaiting_input_ack())
-      test_api.tree_awaiting_input_ack()->OnWindowInputEventAck(0, true);
+    while (test_api.tree_awaiting_input_ack()) {
+      test_api.tree_awaiting_input_ack()->OnWindowInputEventAck(
+          0, mojom::EventResult::HANDLED);
+    }
   }
 
   void DispatchEventAndAckImmediately(const ui::Event& event) {