Move scroll event handlers from layer to layer tree view.

third_party/WebKit/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 662 matching lines @@
         clipParentWebLayer = toWebLayer(parent->compositedLayerMapping()->parentForSublayers());
 
     child->setClipParent(clipParentWebLayer);
 }
 
 void ScrollingCoordinator::willDestroyLayer(PaintLayer* layer)
 {
     m_layersWithTouchRects.remove(layer);
 }
 
-void ScrollingCoordinator::updateHaveScrollEventHandlers()
-{
-    ASSERT(isMainThread());
-    ASSERT(m_page);
-    if (!m_page->mainFrame()->isLocalFrame() || !m_page->deprecatedLocalMainFrame()->view())
-        return;
-
-    // Currently the compositor only cares whether there are scroll handlers anywhere on the page
-    // instead on a per-layer basis. We therefore only update this information for the root
-    // scrolling layer.
-    if (WebLayer* scrollLayer = toWebLayer(m_page->deprecatedLocalMainFrame()->view()->layerForScrolling())) {
-        bool haveHandlers = m_page->frameHost().eventHandlerRegistry().hasEventHandlers(EventHandlerRegistry::ScrollEvent);
-        scrollLayer->setHaveScrollEventHandlers(haveHandlers);
-    }
-}
-
 void ScrollingCoordinator::setShouldUpdateScrollLayerPositionOnMainThread(MainThreadScrollingReasons mainThreadScrollingReasons)
 {
     if (!m_page->mainFrame()->isLocalFrame() || !m_page->deprecatedLocalMainFrame()->view())
         return;
     if (WebLayer* scrollLayer = toWebLayer(m_page->deprecatedLocalMainFrame()->view()->layerForScrolling())) {
         m_lastMainThreadScrollingReasons = mainThreadScrollingReasons;
         if (mainThreadScrollingReasons)
             scrollLayer->addMainThreadScrollingReasons(mainThreadScrollingReasons);
         else
             scrollLayer->clearMainThreadScrollingReasons();
@@ skipping 231 matching lines @@
 
 void ScrollingCoordinator::frameViewRootLayerDidChange(FrameView* frameView)
 {
     ASSERT(isMainThread());
     ASSERT(m_page);
 
     if (!coordinatesScrollingForFrameView(frameView))
         return;
 
     notifyGeometryChanged();
-    updateHaveScrollEventHandlers();
 }
 
 #if OS(MACOSX)
 void ScrollingCoordinator::handleWheelEventPhase(PlatformWheelEventPhase phase)
 {
     ASSERT(isMainThread());
 
     if (!m_page)
         return;
 
@@ skipping 107 matching lines @@
     bool frameIsScrollable = frameView && frameView->isScrollable();
     if (frameIsScrollable != m_wasFrameScrollable)
         return true;
 
     if (WebLayer* scrollLayer = frameView ? toWebLayer(frameView->layerForScrolling()) : nullptr)
         return WebSize(frameView->contentsSize()) != scrollLayer->bounds();
     return false;
 }
 
 } // namespace blink