Revert of Refactor ScrollableArea::setScrollPosition.

third_party/WebKit/Source/platform/scroll/ScrollAnimator.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 172 matching lines @@
 
   if (registerAndScheduleAnimation())
     m_runState = RunState::WaitingToSendToCompositor;
 
   return true;
 }
 
 void ScrollAnimator::adjustAnimationAndSetScrollPosition(
     const DoublePoint& position,
     ScrollType scrollType) {
-  IntSize adjustment =
-      roundedIntPoint(position) -
+  DoublePoint adjustedPos = m_scrollableArea->clampScrollPosition(position);
+  IntSize actualAdjustment =
+      roundedIntPoint(adjustedPos) -
       roundedIntPoint(m_scrollableArea->scrollPositionDouble());
 
-  scrollPositionChanged(position, scrollType);
+  scrollPositionChanged(adjustedPos, scrollType);
 
   if (m_runState == RunState::Idle) {
-    adjustImplOnlyScrollOffsetAnimation(adjustment);
+    adjustImplOnlyScrollOffsetAnimation(actualAdjustment);
   } else if (hasRunningAnimation()) {
-    m_targetOffset += toFloatSize(adjustment);
+    m_targetOffset += toFloatSize(actualAdjustment);
     if (m_animationCurve) {
-      m_animationCurve->applyAdjustment(adjustment);
+      m_animationCurve->applyAdjustment(actualAdjustment);
       if (m_runState != RunState::RunningOnMainThread &&
           registerAndScheduleAnimation())
         m_runState = RunState::RunningOnCompositorButNeedsAdjustment;
     }
   }
 }
 
 void ScrollAnimator::scrollToOffsetWithoutAnimation(const FloatPoint& offset) {
   m_currentPos = offset;
 
@@ skipping 217 matching lines @@
     return false;
   }
   return true;
 }
 
 DEFINE_TRACE(ScrollAnimator) {
   ScrollAnimatorBase::trace(visitor);
 }
 
 }  // namespace blink