Do not (re)start NavigatorGamepad updating once detached.

Source/modules/gamepad/NavigatorGamepad.cpp

 /*
  * Copyright (C) 2011, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 79 matching lines @@
 
 GamepadList* NavigatorGamepad::getGamepads(Navigator& navigator)
 {
     return NavigatorGamepad::from(navigator).gamepads();
 }
 
 GamepadList* NavigatorGamepad::gamepads()
 {
     if (!m_gamepads)
         m_gamepads = GamepadList::create();
-    if (frame() && frame()->domWindow()) {
+    if (frame() && frame()->host()) {
+        // The frame must be attached to start updating.
         startUpdating();
         sampleGamepads<Gamepad>(m_gamepads.get());
     }
     return m_gamepads.get();
 }
 
 void NavigatorGamepad::trace(Visitor* visitor)
 {
     visitor->trace(m_gamepads);
     visitor->trace(m_pendingEvents);
@@ skipping 159 matching lines @@
         if (connectedGamepadChanged || (!oldWasConnected && newIsConnected)) {
             m_pendingEvents.append(newGamepad);
         }
     }
 
     if (!m_pendingEvents.isEmpty())
         m_dispatchOneEventRunner.runAsync();
 }
 
 } // namespace blink