Gamepad: make gamepad events play well with page visibility

Source/modules/gamepad/NavigatorGamepad.h

Index: Source/modules/gamepad/NavigatorGamepad.h
diff --git a/Source/modules/gamepad/NavigatorGamepad.h b/Source/modules/gamepad/NavigatorGamepad.h
index 78cfc18f29e998d4305582e674ac0b950cec6007..c49fd82bf9a516d5520050c691ab1a25bebfbb6d 100644
--- a/Source/modules/gamepad/NavigatorGamepad.h
+++ b/Source/modules/gamepad/NavigatorGamepad.h
@@ -29,6 +29,7 @@
 #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"
@@ -41,6 +42,7 @@ class WebGamepads;
 namespace WebCore {
 
 class Document;
+class Gamepad;
 class GamepadList;
 class Navigator;
 class WebKitGamepadList;
@@ -67,6 +69,9 @@ private:
 
     static const char* supplementName();
 
+    void dispatchOneEvent();
+    void didRemoveGamepadEventListeners();
+
     // DOMWindowProperty
     virtual void willDestroyGlobalObjectInFrame() OVERRIDE;
     virtual void willDetachGlobalObjectFromFrame() OVERRIDE;
@@ -85,6 +90,8 @@ private:
 
     PersistentWillBeMember<GamepadList> m_gamepads;
     PersistentWillBeMember<WebKitGamepadList> m_webkitGamepads;
+    WillBeHeapDeque<Member<Gamepad> > m_pendingEvents;

[tkent, 2014/07/08 23:17:53]

NavigatorGamepad is not garbage-collected on trunk, and Gamepad is
garbage-collected on trunk.  So, This should be
    PersistentHeapDeque<Member<Gamepad> >
on trunk.

Also, NavigatorGamepad will be garbage-collected with ENABLE(OILPAN). So, This
should be
    HeapDeque<Member<Gamepad> >
with ENABLE(OILPAN).

Conclusion:
Add
#define PersistentHeapDequeWillBeHeapDeque WebCore::HeapDeque
#define PersistentHeapDequeWillBeHeapDeque WebCOre::PersistentHeapDeque
to platform/heap/Handle.h like PersistentHeapHashSetWillBeHeapHashSet, and use
PersistentHeapDequeWillBeHeapDeque<Member<Gamepad> > in NavigatorGamepad.

+    AsyncMethodRunner<NavigatorGamepad> m_dispatchOneEventRunner;
 };
 
 } // namespace WebCore