Revert of Refactor ScrollableArea::setScrollPosition.

third_party/WebKit/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 3546 matching lines @@
     scrollSize.clampNegativeToZero();
     return orientation == HorizontalScrollbar ? scrollSize.width()
                                               : scrollSize.height();
   }
 
   return scrollbar->totalSize() - scrollbar->visibleSize();
 }
 
 void FrameView::setScrollOffset(const DoublePoint& offset,
                                 ScrollType scrollType) {
+  // TODO(skobes): We shouldn't have to clamp here; instead we should update callers
+  // ScrollableArea::scrollPositionChanged to only pass clamped offsets.
+  DoublePoint newPosition = clampScrollPosition(offset);
+
   DoublePoint oldPosition = m_scrollPosition;
-  DoubleSize scrollDelta = offset - oldPosition;
+  DoubleSize scrollDelta = newPosition - oldPosition;
   if (scrollDelta.isZero())
     return;
 
   if (RuntimeEnabledFeatures::rootLayerScrollingEnabled()) {
     // Don't scroll the FrameView!
     ASSERT_NOT_REACHED();
   }
 
-  m_scrollPosition = offset;
+  m_scrollPosition = newPosition;
 
   if (!scrollbarsSuppressed())
     m_pendingScrollDelta += scrollDelta;
 
   clearFragmentAnchor();
   updateLayersAndCompositingAfterScrollIfNeeded(scrollDelta);
 
   Document* document = m_frame->document();
   document->enqueueScrollEventForNode(document);
 
@@ skipping 928 matching lines @@
 }
 
 bool FrameView::canThrottleRendering() const {
   if (!RuntimeEnabledFeatures::renderingPipelineThrottlingEnabled())
     return false;
   return m_subtreeThrottled ||
          (m_hiddenForThrottling && m_crossOriginForThrottling);
 }
 
 }  // namespace blink