Gamepad: make gamepad events play well with page visibility

Source/modules/gamepad/NavigatorGamepad.h

 /*
  * 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 11 matching lines @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  * DAMAGE.
  */
 
 #ifndef NavigatorGamepad_h
 #define NavigatorGamepad_h
 
 #include "core/frame/DOMWindowLifecycleObserver.h"
 #include "core/frame/DOMWindowProperty.h"
 #include "core/frame/DeviceEventControllerBase.h"
+#include "platform/AsyncMethodRunner.h"
 #include "platform/Supplementable.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/WebGamepads.h"
+#include "wtf/Deque.h"
 
 namespace blink {
 class WebGamepad;
 class WebGamepads;
 }
 
 namespace WebCore {
 
 class Document;
+class Gamepad;
 class GamepadList;
 class Navigator;
 class WebKitGamepadList;
 
 class NavigatorGamepad FINAL : public NoBaseWillBeGarbageCollectedFinalized<NavigatorGamepad>, public WillBeHeapSupplement<Navigator>, public DOMWindowProperty, public DeviceEventControllerBase, public DOMWindowLifecycleObserver {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(NavigatorGamepad);
 public:
     static NavigatorGamepad* from(Document&);
     static NavigatorGamepad& from(Navigator&);
     virtual ~NavigatorGamepad();
 
     static WebKitGamepadList* webkitGetGamepads(Navigator&);
     static GamepadList* getGamepads(Navigator&);
 
     WebKitGamepadList* webkitGamepads();
     GamepadList* gamepads();
 
     virtual void trace(Visitor*);
 
     void didConnectOrDisconnectGamepad(unsigned index, const blink::WebGamepad&, bool connected);
 
 private:
     explicit NavigatorGamepad(LocalFrame*);
 
     static const char* supplementName();
 
+    void dispatchOneEvent();
+    void didRemoveGamepadEventListeners();
+
     // DOMWindowProperty
     virtual void willDestroyGlobalObjectInFrame() OVERRIDE;
     virtual void willDetachGlobalObjectFromFrame() OVERRIDE;
 
     // DeviceEventControllerBase
     virtual void registerWithDispatcher() OVERRIDE;
     virtual void unregisterWithDispatcher() OVERRIDE;
     virtual bool hasLastData() OVERRIDE;
     virtual void didUpdateData() OVERRIDE;
     virtual void pageVisibilityChanged() OVERRIDE;
 
     // DOMWindowLifecycleObserver
     virtual void didAddEventListener(LocalDOMWindow*, const AtomicString&) OVERRIDE;
     virtual void didRemoveEventListener(LocalDOMWindow*, const AtomicString&) OVERRIDE;
     virtual void didRemoveAllEventListeners(LocalDOMWindow*) OVERRIDE;
 
     PersistentWillBeMember<GamepadList> m_gamepads;
     PersistentWillBeMember<WebKitGamepadList> m_webkitGamepads;
+    AsyncMethodRunner<NavigatorGamepad> m_dispatchOneEventRunner;
+    Deque<Gamepad*> m_pendingEvents;

[abarth-chromium, 2014/07/07 22:11:04]

Don't we need to trace these Gamepad* so that they don't get GCed?

 };
 
 } // namespace WebCore
 
 #endif // NavigatorGamepad_h