CompositingReasonFinder should use a virtual function instead of a nest of branches

Source/core/rendering/compositing/CompositingTriggers.h

 /*
+ * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple, Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+ * Copyright (C) 2012 Samsung Electronics. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
- *
  */
 
-#ifndef PopupMenu_h
-#define PopupMenu_h
-
-#include "platform/PlatformExport.h"
-#include "wtf/RefCounted.h"
+#ifndef CompositingTriggers_h
+#define CompositingTriggers_h
 
 namespace WebCore {
 
-class FloatQuad;
-class FrameView;
-class IntRect;
-class IntSize;
+enum CompositingTrigger {
+    ThreeDTransformTrigger = 1 << 0,
+    VideoTrigger = 1 << 1,
+    PluginTrigger = 1 << 2,
+    CanvasTrigger = 1 << 3,
+    AnimationTrigger = 1 << 4,
+    FilterTrigger = 1 << 5,
+    ScrollableInnerFrameTrigger = 1 << 6,
+    AllCompositingTriggers = 0xFFFFFFFF
+};
 
-class PopupMenu : public RefCounted<PopupMenu> {
-public:
-    virtual ~PopupMenu() { }
-    virtual void show(const FloatQuad& controlPosition, const IntSize& controlSize, int index) = 0;
-    virtual void hide() = 0;
-    virtual void updateFromElement() = 0;
-    virtual void disconnectClient() = 0;
-};
+typedef unsigned CompositingTriggerFlags;
 
 }
 
-#endif // PopupMenu_h
+#endif