In mushrome, keep the state of the cursor locally.

ash/wm/native_cursor_manager_ash_mus.cc

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/wm/native_cursor_manager_ash_mus.h"
 
 #include "ash/display/cursor_window_controller.h"
 #include "ash/display/window_tree_host_manager.h"
 #include "ash/shell.h"
 #include "ash/shell_port.h"
@@ skipping 26 matching lines @@
 #endif
   } else {
     mojo_cursor = ui::CursorData(cursor.native_type());
   }
 
   // As the window manager, tell mus to use |mojo_cursor| everywhere. We do
   // this instead of trying to set per-window because otherwise we run into the
   // event targeting issue.
   ShellPort::Get()->SetGlobalOverrideCursor(mojo_cursor);
 
+  // Make sure the local state is set properly, so that local queries show that
+  // we set the cursor.
+  aura::Window::Windows root_windows = Shell::Get()->GetAllRootWindows();
+  for (aura::Window::Windows::iterator iter = root_windows.begin();

[sky, 2017/06/23 23:31:28]

for (aura::Window* root : Shell::Get()->GetAllRootWindows())

+       iter != root_windows.end(); ++iter)
+    (*iter)->GetHost()->SetCursor(cursor);
+
   Shell::Get()
       ->window_tree_host_manager()
       ->cursor_window_controller()
       ->SetCursor(cursor);
 }
 
 void NotifyCursorVisibilityChange(bool visible) {
   // Communicate the cursor visibility state to the mus server.
   if (visible)
     ShellPort::Get()->ShowCursor();
@@ skipping 141 matching lines @@
   } else {
     disabled_cursor_location_ = aura::Env::GetInstance()->last_mouse_location();
   }
 
   SetVisibility(delegate->IsCursorVisible(), delegate);
 
   NotifyMouseEventsEnableStateChange(enabled);
 }
 
 }  // namespace ash