Add support for DOM Level 3 WheelEvent

Source/core/dom/Node.cpp

Index: Source/core/dom/Node.cpp
diff --git a/Source/core/dom/Node.cpp b/Source/core/dom/Node.cpp
index 439fef932015e5530f27f07b7a22f2d4cfdcc86e..b65f61287930f26097d59c0ec82e1b1f6e2d0880 100644
--- a/Source/core/dom/Node.cpp
+++ b/Source/core/dom/Node.cpp
@@ -2151,7 +2151,13 @@ void Node::didMoveToNewDocument(Document* oldDocument)
         if (AXObjectCache* cache = oldDocument->existingAXObjectCache())
             cache->remove(this);
 
-    const EventListenerVector& wheelListeners = getEventListeners(eventNames().mousewheelEvent);
+    const EventListenerVector& mousewheelListeners = getEventListeners(eventNames().mousewheelEvent);
+    for (size_t i = 0; i < mousewheelListeners.size(); ++i) {
+        oldDocument->didRemoveWheelEventHandler();
+        document()->didAddWheelEventHandler();
+    }
+
+    const EventListenerVector& wheelListeners = getEventListeners(eventNames().wheelEvent);
     for (size_t i = 0; i < wheelListeners.size(); ++i) {
         oldDocument->didRemoveWheelEventHandler();
         document()->didAddWheelEventHandler();
@@ -2184,7 +2190,7 @@ static inline bool tryAddEventListener(Node* targetNode, const AtomicString& eve
 
     if (Document* document = targetNode->document()) {
         document->addListenerTypeIfNeeded(eventType);
-        if (eventType == eventNames().mousewheelEvent)
+        if (eventType == eventNames().wheelEvent || eventType == eventNames().mousewheelEvent)
             document->didAddWheelEventHandler();
         else if (eventNames().isTouchEventType(eventType))
             document->didAddTouchEventHandler(targetNode);
@@ -2206,7 +2212,7 @@ static inline bool tryRemoveEventListener(Node* targetNode, const AtomicString&
     // FIXME: Notify Document that the listener has vanished. We need to keep track of a number of
     // listeners for each type, not just a bool - see https://bugs.webkit.org/show_bug.cgi?id=33861
     if (Document* document = targetNode->document()) {
-        if (eventType == eventNames().mousewheelEvent)
+        if (eventType == eventNames().wheelEvent || eventType == eventNames().mousewheelEvent)
             document->didRemoveWheelEventHandler();
         else if (eventNames().isTouchEventType(eventType))
             document->didRemoveTouchEventHandler(targetNode);
@@ -2462,6 +2468,8 @@ bool Node::dispatchBeforeLoadEvent(const String& sourceURL)
 
 bool Node::dispatchWheelEvent(const PlatformWheelEvent& event)
 {
+    // We dispatch both the standard wheel event and the non-standard mousewheel one
+    // for backward compatibility.
     return EventDispatcher::dispatchEvent(this, WheelEventDispatchMediator::create(event, document()->defaultView()));
 }
 
@@ -2513,7 +2521,7 @@ void Node::defaultEventHandler(Event* event)
             }
         }
 #endif
-    } else if (eventType == eventNames().mousewheelEvent && event->hasInterface(eventNames().interfaceForWheelEvent)) {
+    } else if ((eventType == eventNames().wheelEvent || eventType == eventNames().mousewheelEvent) && event->hasInterface(eventNames().interfaceForWheelEvent)) {
         WheelEvent* wheelEvent = static_cast<WheelEvent*>(event);
 
         // If we don't have a renderer, send the wheel event to the first node we find with a renderer.