Migrate wheel events to EventHandlerRegistry

Source/core/frame/LocalFrame.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Simon Hausmann <hausmann@kde.org>
  *                     2000 Stefan Schimanski <1Stein@gmx.de>
  *                     2001 George Staikos <staikos@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2005 Alexey Proskuryakov <ap@nypop.com>
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
@@ skipping 15 matching lines @@
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #include "config.h"
 #include "core/frame/LocalFrame.h"
 
 #include "RuntimeEnabledFeatures.h"
 #include "bindings/v8/ScriptController.h"
 #include "core/dom/DocumentType.h"
-#include "core/dom/WheelController.h"
 #include "core/editing/Editor.h"
 #include "core/editing/FrameSelection.h"
 #include "core/editing/InputMethodController.h"
 #include "core/editing/SpellChecker.h"
 #include "core/editing/htmlediting.h"
 #include "core/editing/markup.h"
 #include "core/events/Event.h"
 #include "core/fetch/ResourceFetcher.h"
 #include "core/frame/DOMWindow.h"
+#include "core/frame/EventHandlerRegistry.h"
 #include "core/frame/FrameConsole.h"
 #include "core/frame/FrameHost.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/Settings.h"
 #include "core/html/HTMLFrameElementBase.h"
 #include "core/inspector/InspectorInstrumentation.h"
 #include "core/loader/FrameLoaderClient.h"
 #include "core/page/Chrome.h"
 #include "core/page/EventHandler.h"
 #include "core/page/FocusController.h"
@@ skipping 444 matching lines @@
 
 void LocalFrame::deviceOrPageScaleFactorChanged()
 {
     document()->mediaQueryAffectingValueChanged();
     for (RefPtr<LocalFrame> child = tree().firstChild(); child; child = child->tree().nextSibling())
         child->deviceOrPageScaleFactorChanged();
 }
 
 void LocalFrame::notifyChromeClientWheelEventHandlerCountChanged() const
 {
+    // TODO(skyostil): No-one is using this information, so remove this code.
     // 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 = m_host->eventHandlerRegistry();
+    unsigned count = registry.externalEventHandlerCount(EventHandlerRegistry::WheelEvent);
+    const EventTargetSet* targets = registry.eventHandlerTargets(EventHandlerRegistry::WheelEvent);
+    if (targets) {

[ojan, 2014/06/02 21:23:04]

There's no official style rule, but we typically do the following:
if (const EventTargetSet* targets =
registry.eventHandlerTargets(EventHandlerRegistry::WheelEvent))

It scopes the variable to the if clause and since you're declaring the variable
here, there's no possibility of silly bugs by accidentally typing == or
something like that.

[Sami, 2014/06/03 15:57:45]

Ah yes, that's a good idea. Done.

+        for (EventTargetSet::const_iterator iter = targets->begin(); iter != targets->end(); ++iter)
+            count += iter->value;
     }
 
     m_host->chrome().client().numWheelEventHandlersChanged(count);
 }
 
 bool LocalFrame::isURLAllowed(const KURL& url) const
 {
     // We allow one level of self-reference because some sites depend on that,
     // but we don't allow more than one.
     if (page()->subframeCount() >= Page::maxNumberOfFrames)
@@ skipping 123 matching lines @@
 LocalFrame* LocalFrame::localFrameRoot()
 {
     LocalFrame* curFrame = this;
     while (curFrame && curFrame->tree().parent() && curFrame->tree().parent()->isLocalFrame())
         curFrame = curFrame->tree().parent();
 
     return curFrame;
 }
 
 } // namespace WebCore