Expose scroll customization for touch to JS (behind REF).

Source/core/dom/Element.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003-2011, 2013, 2014 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 44 matching lines @@
 class ElementRareData;
 class ElementShadow;
 class ExceptionState;
 class Image;
 class IntSize;
 class Locale;
 class MutableStylePropertySet;
 class PropertySetCSSStyleDeclaration;
 class PseudoElement;
 class ScrollState;
+class ScrollStateCallback;
 class ScrollToOptions;
 class ShadowRoot;
 class ShadowRootInit;
 class StylePropertySet;
 
 enum SpellcheckAttributeState {
     SpellcheckAttributeTrue,
     SpellcheckAttributeFalse,
     SpellcheckAttributeDefault
 };
@@ skipping 88 matching lines @@
     // will be returned. This is not a trivial getter and its return value should be cached
     // for performance.
     AttributeCollection attributes() const;
     // This variant will not update the potentially invalid attributes. To be used when not interested
     // in style attribute or one of the SVG animation attributes.
     AttributeCollection attributesWithoutUpdate() const;
 
     void scrollIntoView(bool alignToTop = true);
     void scrollIntoViewIfNeeded(bool centerIfNeeded = true);
 
-    void distributeScroll(ScrollState&);
-    void applyScroll(ScrollState&);
-
     int offsetLeft();
     int offsetTop();
     int offsetWidth();
     int offsetHeight();
 
     Element* offsetParent();
     int clientLeft();
     int clientTop();
     int clientWidth();
     int clientHeight();
@@ skipping 177 matching lines @@
 
     KURL getURLAttribute(const QualifiedName&) const;
     KURL getNonEmptyURLAttribute(const QualifiedName&) const;
 
     virtual const AtomicString imageSourceURL() const;
     virtual Image* imageContents() { return nullptr; }
 
     virtual void focus(bool restorePreviousSelection = true, WebFocusType = WebFocusTypeNone);
     virtual void updateFocusAppearance(bool restorePreviousSelection);
     virtual void blur();
+
+    void setDistributeScroll(ScrollStateCallback*);
+    ScriptValue distributeScroll(ScriptState*);

[haraken, 2015/06/30 07:08:30]

Would it be possible to:

- make distributeScroll return ScriptStateCallback*
- let the binding layer call toV8(distributeScroll()), which converts the
ScriptStateCallback* to a V8 wrapper

This is a common way to convert a DOM object to a V8 wrapper. You can define the
toV8 method in ToV8.h.

+    void nativeDistributeScroll(ScrollState&);
+    void setApplyScroll(ScrollStateCallback*);
+    ScriptValue applyScroll(ScriptState*);

[haraken, 2015/06/30 07:08:30]

Ditto.

+    void nativeApplyScroll(ScrollState&);
+
+    void callDistributeScroll(ScrollState&);
+    void callApplyScroll(ScrollState&);
+
     // Whether this element can receive focus at all. Most elements are not
     // focusable but some elements, such as form controls and links, are. Unlike
     // layoutObjectIsFocusable(), this method may be called when layout is not up to
     // date, so it must not use the layoutObject to determine focusability.
     virtual bool supportsFocus() const;
     // Whether the node can actually be focused.
     bool isFocusable() const;
     bool isFocusedElementInDocument() const;
     virtual bool isKeyboardFocusable() const;
     virtual bool isMouseFocusable() const;
@@ skipping 497 matching lines @@
     static PassRefPtrWillBeRawPtr<T> create(const QualifiedName&, Document&)
 #define DEFINE_ELEMENT_FACTORY_WITH_TAGNAME(T) \
     PassRefPtrWillBeRawPtr<T> T::create(const QualifiedName& tagName, Document& document) \
     { \
         return adoptRefWillBeNoop(new T(tagName, document)); \
     }
 
 } // namespace
 
 #endif // Element_h