Remove special wheel handling path from ScrollableArea

Source/platform/scroll/ScrollAnimatorNone.cpp

 /*
  * Copyright (c) 2011, Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 406 matching lines @@
 
     // If the individual input setting is disabled, bail.
     if (!parameters.m_isEnabled)
         return ScrollAnimator::userScroll(orientation, granularity, step, delta);
 
     // This is an animatable scroll. Set the animation in motion using the appropriate parameters.
     float scrollableSize = static_cast<float>(m_scrollableArea->scrollSize(orientation));
 
     PerAxisData& data = (orientation == VerticalScrollbar) ? m_verticalData : m_horizontalData;
     bool needToScroll = data.updateDataFromParameters(step, delta, scrollableSize, WTF::monotonicallyIncreasingTime(), &parameters);
+    float unusedDelta = needToScroll ? delta - (data.m_desiredPosition - *data.m_currentPosition) : delta;
     if (needToScroll && !animationTimerActive()) {
         m_startTime = data.m_startTime;
         animationWillStart();
         animationTimerFired();
         scrollableArea()->registerForAnimation();
     }
-    return ScrollResultOneDimensional(needToScroll);
+    return ScrollResultOneDimensional(needToScroll, unusedDelta);
 }
 
 void ScrollAnimatorNone::scrollToOffsetWithoutAnimation(const FloatPoint& offset)
 {
     m_currentPosX = offset.x();
     m_currentPosY = offset.y();
 
     // Must be called after setting the position since canceling the animation resets
     // the desired position to the current.
     cancelAnimations();
@@ skipping 82 matching lines @@
     return m_animationActive;
 }
 
 void ScrollAnimatorNone::stopAnimationTimerIfNeeded()
 {
     if (animationTimerActive())
         m_animationActive = false;
 }
 
 } // namespace blink