Remove special wheel handling path from ScrollableArea

Source/core/frame/RootFrameViewport.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/frame/RootFrameViewport.h"
 
 #include "core/frame/FrameView.h"
 #include "core/layout/ScrollAlignment.h"
 #include "platform/geometry/DoubleRect.h"
@@ skipping 75 matching lines @@
 
     DoublePoint clampedPosition = clampScrollPosition(position);
     ScrollableArea::setScrollPosition(clampedPosition, scrollType, scrollBehavior);
 }
 
 ScrollBehavior RootFrameViewport::scrollBehaviorStyle() const
 {
     return layoutViewport().scrollBehaviorStyle();
 }
 
-ScrollResult RootFrameViewport::handleWheel(const PlatformWheelEvent& event)
-{
-    updateScrollAnimator();
-
-    ScrollableArea& primary = !m_invertScrollOrder ? layoutViewport() : visualViewport();
-    ScrollableArea& secondary = !m_invertScrollOrder ? visualViewport() : layoutViewport();
-
-    ScrollResult viewScrollResult = primary.handleWheel(event);
-
-    // The visual viewport will only accept pixel scrolls.
-    if (!event.canScroll() || event.granularity() == ScrollByPageWheelEvent)
-        return viewScrollResult;
-
-    // TODO(sataya.m) : The delta in PlatformWheelEvent is negative when scrolling the
-    // wheel towards the user, so negate it to get the scroll delta that should be applied
-    // to the page. unusedScrollDelta computed in the ScrollResult is also negative. Say
-    // there is WheelEvent({0, -10} and page scroll by 2px and unusedScrollDelta computed
-    // is {0, -8}. Due to which we have to negate the unusedScrollDelta to obtain the expected
-    // animation.Please address http://crbug.com/504389.
-    DoublePoint oldOffset = secondary.scrollPositionDouble();
-    DoublePoint locationDelta;
-    if (viewScrollResult.didScroll()) {
-        locationDelta = -DoublePoint(viewScrollResult.unusedScrollDeltaX, viewScrollResult.unusedScrollDeltaY);
-    } else {
-        if (event.railsMode() != PlatformEvent::RailsModeVertical)
-            locationDelta.setX(-event.deltaX());
-        if (event.railsMode() != PlatformEvent::RailsModeHorizontal)
-            locationDelta.setY(-event.deltaY());
-    }
-
-    DoublePoint targetPosition = secondary.clampScrollPosition(
-        secondary.scrollPositionDouble() + toDoubleSize(locationDelta));
-    secondary.setScrollPosition(targetPosition, UserScroll);
-
-    DoublePoint usedLocationDelta(secondary.scrollPositionDouble() - oldOffset);
-
-    bool didScrollX = viewScrollResult.didScrollX || usedLocationDelta.x();
-    bool didScrollY = viewScrollResult.didScrollY || usedLocationDelta.y();
-    return ScrollResult(didScrollX, didScrollY, -viewScrollResult.unusedScrollDeltaX - usedLocationDelta.x(), -viewScrollResult.unusedScrollDeltaY - usedLocationDelta.y());
-}
-
 LayoutRect RootFrameViewport::scrollIntoView(const LayoutRect& rectInContent, const ScrollAlignment& alignX, const ScrollAlignment& alignY)
 {
     // We want to move the rect into the viewport that excludes the scrollbars so we intersect
     // the visual viewport with the scrollbar-excluded frameView content rect. However, we don't
     // use visibleContentRect directly since it floors the scroll position. Instead, we use
     // FrameView::scrollPositionDouble and construct a LayoutRect from that (the FrameView size
     // is always integer sized.
 
     LayoutRect frameRectInContent = LayoutRect(
         layoutViewport().scrollPositionDouble(),
@@ skipping 189 matching lines @@
 }
 
 DEFINE_TRACE(RootFrameViewport)
 {
     visitor->trace(m_visualViewport);
     visitor->trace(m_layoutViewport);
     ScrollableArea::trace(visitor);
 }
 
 } // namespace blink