Migrate wheel events to EventHandlerRegistry

Source/core/page/scrolling/ScrollingCoordinator.cpp

 /*
  * Copyright (C) 2011 Apple 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 13 matching lines @@
  */
 
 #include "config.h"
 
 #include "core/page/scrolling/ScrollingCoordinator.h"
 
 #include "RuntimeEnabledFeatures.h"
 #include "core/dom/Document.h"
 #include "core/dom/FullscreenElementStack.h"
 #include "core/dom/Node.h"
-#include "core/dom/WheelController.h"
 #include "core/frame/EventHandlerRegistry.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
 #include "core/html/HTMLElement.h"
 #include "core/page/Page.h"
 #include "core/plugins/PluginView.h"
 #include "core/rendering/RenderGeometryMap.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/compositing/CompositedLayerMapping.h"
@@ skipping 611 matching lines @@
 }
 
 void ScrollingCoordinator::updateHaveWheelEventHandlers()
 {
     ASSERT(isMainThread());
     ASSERT(m_page);
     if (!m_page->mainFrame()->view())
         return;
 
     if (WebLayer* scrollLayer = toWebLayer(m_page->mainFrame()->view()->layerForScrolling())) {
-        unsigned wheelEventHandlerCount = 0;
-
-        for (LocalFrame* frame = m_page->mainFrame(); frame; frame = frame->tree().traverseNext()) {
-            wheelEventHandlerCount += WheelController::from(*frame->document())->wheelEventHandlerCount();
-        }
-
-        scrollLayer->setHaveWheelEventHandlers(wheelEventHandlerCount);
+        bool haveHandlers = m_page->frameHost().eventHandlerRegistry().hasEventHandlers(EventHandlerRegistry::WheelEvent);
+        scrollLayer->setHaveWheelEventHandlers(haveHandlers);
     }
 }
 
 void ScrollingCoordinator::updateHaveScrollEventHandlers()
 {
     ASSERT(isMainThread());
     ASSERT(m_page);
     if (!m_page->mainFrame()->view())
         return;
 
@@ skipping 293 matching lines @@
     bool frameIsScrollable = frameView && frameView->isScrollable();
     if (frameIsScrollable != m_wasFrameScrollable)
         return true;
 
     if (WebLayer* scrollLayer = frameView ? toWebLayer(frameView->layerForScrolling()) : 0)
         return blink::WebSize(frameView->contentsSize()) != scrollLayer->bounds();
     return false;
 }
 
 } // namespace WebCore