Add EventHandlerRegistry

Source/core/frame/LocalFrame.cpp

Index: Source/core/frame/LocalFrame.cpp
diff --git a/Source/core/frame/LocalFrame.cpp b/Source/core/frame/LocalFrame.cpp
index adfa8ad6ddaa9f1f29dc00c7fc6da1c1ea667bcf..e767e49410fc2ac0b586d13992aa3fe2cf84cf26 100644
--- a/Source/core/frame/LocalFrame.cpp
+++ b/Source/core/frame/LocalFrame.cpp
@@ -33,7 +33,7 @@
 #include "RuntimeEnabledFeatures.h"
 #include "bindings/v8/ScriptController.h"
 #include "core/dom/DocumentType.h"
-#include "core/dom/WheelController.h"
+#include "core/dom/EventHandlerRegistry.h"
 #include "core/editing/Editor.h"
 #include "core/editing/FrameSelection.h"
 #include "core/editing/InputMethodController.h"
@@ -466,12 +466,13 @@ void LocalFrame::notifyChromeClientWheelEventHandlerCountChanged() const
     // Ensure that this method is being called on the main frame of the page.
     ASSERT(isMainFrame());
 
-    unsigned count = 0;
-    for (const LocalFrame* frame = this; frame; frame = frame->tree().traverseNext()) {
-        if (frame->document())
-            count += WheelController::from(*frame->document())->wheelEventHandlerCount();
+    EventHandlerRegistry* registry = EventHandlerRegistry::from(*document());
+    unsigned count = registry->externalEventHandlerCount(EventHandlerRegistry::WheelEvent);
+    const EventTargetSet* targets = registry->eventHandlerTargets(EventHandlerRegistry::WheelEvent);
+    if (targets) {
+        for (EventTargetSet::const_iterator iter = targets->begin(); iter != targets->end(); ++iter)
+            count += iter->value;
     }
-
     m_host->chrome().client().numWheelEventHandlersChanged(count);
 }