Remove ScrollableArea::notifyScrollPositionChanged and cleanup scroll animators.

Source/core/frame/FrameView.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 1471 matching lines @@
     // Only do a layout if changes have occurred that make it necessary.
     LayoutView* layoutView = this->layoutView();
     if (layoutView && layoutView->needsLayout())
         layout();
     else
         scrollToAnchor();
 }
 
 void FrameView::setScrollPosition(const DoublePoint& scrollPoint, ScrollType scrollType, ScrollBehavior scrollBehavior)
 {
-    cancelProgrammaticScrollAnimation();
     m_maintainScrollPositionAnchor = nullptr;
 
     DoublePoint newScrollPosition = adjustScrollPositionWithinRange(scrollPoint);
     if (newScrollPosition == scrollPositionDouble())
         return;
 
     if (scrollBehavior == ScrollBehaviorAuto)
         scrollBehavior = scrollBehaviorStyle();
 
-    if (scrollBehavior == ScrollBehaviorInstant) {
-        DoubleSize newOffset(newScrollPosition.x(), newScrollPosition.y());
-        // TODO(bokan): Why do we need to go through updateScrollbars? If not, we can
-        // just delete this whole method and use the base version.
-        updateScrollbars(newOffset);
-    } else {
-        ScrollableArea::setScrollPosition(newScrollPosition, ProgrammaticScroll, ScrollBehaviorSmooth);
-    }
+    ScrollableArea::setScrollPosition(newScrollPosition, scrollType, scrollBehavior);
 }
 
 void FrameView::setElasticOverscroll(const FloatSize& elasticOverscroll)
 {
     m_elasticOverscroll = elasticOverscroll;
     if (m_horizontalScrollbar) {
         float delta = elasticOverscroll.width() - m_horizontalScrollbar->elasticOverscroll();
         if (delta != 0) {
             m_horizontalScrollbar->setElasticOverscroll(elasticOverscroll.width());
             scrollAnimator()->notifyContentAreaScrolled(FloatSize(delta, 0));
@@ skipping 2490 matching lines @@
 
     if (!graphicsLayer)
         return;
 
     DeprecatedPaintLayer::mapRectToPaintInvalidationBacking(localFrame->contentLayoutObject(), paintInvalidationContainer, viewRect);
 
     graphicsLayerTimingRequests.add(graphicsLayer, Vector<std::pair<int64_t, WebRect>>()).storedValue->value.append(std::make_pair(m_frame->frameID(), enclosingIntRect(viewRect)));
 }
 
 } // namespace blink