Oilpan: Build fix after r170454

Source/modules/push_messaging/PushManager.h

 // Copyright 2014 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.
 
 #ifndef PushManager_h
 #define PushManager_h
 
 #include "bindings/v8/ScriptWrappable.h"
+#include "heap/Handle.h"
 #include "wtf/RefCounted.h"
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
 class ExecutionContext;
 class ScriptPromise;
 
-class PushManager FINAL : public RefCountedWillBeRefCountedGarbageCollected<PushManager>, public ScriptWrappable {
+class PushManager FINAL : public RefCountedWillBeGarbageCollectedFinalized<PushManager>, public ScriptWrappable {

[Peter Beverloo, 2014/03/31 19:08:07]

Could you confirm my understanding of this change?

Very similar classes, e.g. Notification and BatteryManager, are
RefCountedWillBeRefCountedGarbageCollected, but they have to be given that
events can be fired on them, and they thus have to be kept alive.  This is not
the case for PushManager, which is not an EventTarget, and can therefore be GCed
the moment a call to navigator.push.register() (or other future methods) is
done. Therefore the reference counting is not needed, and we can rely on just
GC.

[sof, 2014/03/31 19:32:40]

Yes, an event target will have to be kept alive for as long as there are
listeners attached (which aren't heap allocated, so a ref count is separately
kept.)

As you say, there are no heap-external PushManager references, so
*RefCountedGarbageCollected is not needed for it, *GarbageCollectedFinalized
suffices. If it sprouts events later, we can add it then.

Do notice that the Navigator supplementable will trace&keep NavigatorPushManager
(a supplement of it) alive. Which again will keep PushManager alive. So, the
push manager&supplement will stay around for as long as the Navigator object
does.

 public:
-    static PassRefPtrWillBeRawPtr<PushManager> create() { return adoptRefWillBeNoop(new PushManager()); }
+    static PassRefPtrWillBeRawPtr<PushManager> create()
+    {
+        return adoptRefWillBeNoop(new PushManager());
+    }
     virtual ~PushManager();
 
     ScriptPromise registerPushMessaging(ExecutionContext*, const String& senderId);
 
+    void trace(Visitor*) { }
+
 private:
     PushManager();
 };
 
 } // namespace WebCore
 
 #endif // PushManager_h