Update event states in Env when target window has been destroyed.

ui/aura/mus/window_tree_client.cc

Index: ui/aura/mus/window_tree_client.cc
diff --git a/ui/aura/mus/window_tree_client.cc b/ui/aura/mus/window_tree_client.cc
index d272bad304b7fd8c3e26437a9cf8df824b03117e..46193428a31982c1d13b079b3bacd2a5f799c017 100644
--- a/ui/aura/mus/window_tree_client.cc
+++ b/ui/aura/mus/window_tree_client.cc
@@ -29,6 +29,7 @@
 #include "ui/aura/client/drag_drop_client.h"
 #include "ui/aura/client/transient_window_client.h"
 #include "ui/aura/env.h"
+#include "ui/aura/env_input_state_controller.h"
 #include "ui/aura/mus/capture_synchronizer.h"
 #include "ui/aura/mus/drag_drop_controller_mus.h"
 #include "ui/aura/mus/focus_synchronizer.h"
@@ -47,6 +48,7 @@
 #include "ui/aura/mus/window_tree_host_mus_init_params.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_delegate.h"
+#include "ui/aura/window_event_dispatcher.h"
 #include "ui/aura/window_tracker.h"
 #include "ui/base/layout.h"
 #include "ui/base/ui_base_types.h"
@@ -1302,8 +1304,20 @@ void WindowTreeClient::OnWindowInputEvent(uint32_t event_id,
                                       window ? window->GetWindow() : nullptr);
   }
 
-  // TODO: use |display_id| to find host and send there.
+  // If the window has already been deleted, use |event| to update event states
+  // kept in aura::Env. Any WindowTreeHost should be okay to get
+  // aura::EnvInputStateController from since these are global states.
   if (!window || !window->GetWindow()->GetHost()) {
+    DCHECK(!roots_.empty());
+    EnvInputStateController* env_controller =
+        GetWindowTreeHostMus(*roots_.begin())->dispatcher()->env_controller();
+    std::unique_ptr<ui::Event> mapped_event = MapEvent(*event.get());
+    if (mapped_event->IsMouseEvent()) {
+      env_controller->UpdateStateForMouseEvent(nullptr,
+                                               *mapped_event->AsMouseEvent());
+    } else if (mapped_event->IsTouchEvent()) {
+      env_controller->UpdateStateForTouchEvent(*mapped_event->AsTouchEvent());
+    }
     tree_->OnWindowInputEventAck(event_id, ui::mojom::EventResult::UNHANDLED);
     return;
   }