Remove more scrolling code from Sky

sky/engine/core/rendering/RenderBoxModelObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 424 matching lines @@
     LayoutUnit pRight = includeRightEdge ? paddingRight() : LayoutUnit();
 
     GraphicsContextStateSaver clipWithScrollingStateSaver(*context, clippedWithLocalScrolling);
     LayoutRect scrolledPaintRect = rect;
     if (clippedWithLocalScrolling) {
         // Clip to the overflow area.
         RenderBox* thisBox = toRenderBox(this);
         context->clip(thisBox->overflowClipRect(rect.location()));
 
         // Adjust the paint rect to reflect a scrolled content box with borders at the ends.
-        IntSize offset = thisBox->scrolledContentOffset();
-        scrolledPaintRect.move(-offset);
-        scrolledPaintRect.setWidth(bLeft + thisBox->scrollWidth() + bRight);
-        scrolledPaintRect.setHeight(borderTop() + thisBox->scrollHeight() + borderBottom());
+        scrolledPaintRect.setWidth(bLeft + thisBox->clientWidth() + bRight);
+        scrolledPaintRect.setHeight(borderTop() + thisBox->clientHeight() + borderBottom());
     }
 
     GraphicsContextStateSaver backgroundClipStateSaver(*context, false);
     IntRect maskRect;
 
     switch (bgLayer.clip()) {
     case PaddingFillBox:
     case ContentFillBox: {
         if (clipToBorderRadius)
             break;
@@ skipping 266 matching lines @@
 {
     LayoutUnit left = 0;
     LayoutUnit top = 0;
     IntSize positioningAreaSize;
     IntRect snappedPaintRect = pixelSnappedIntRect(paintRect);
 
     // Determine the background positioning area and set destRect to the background painting area.
     // destRect will be adjusted later if the background is non-repeating.
     // FIXME: transforms spec says that fixed backgrounds behave like scroll inside transforms.
     bool fixedAttachment = fillLayer.attachment() == FixedBackgroundAttachment;
-
-    if (RuntimeEnabledFeatures::fastMobileScrollingEnabled()) {
-        // As a side effect of an optimization to blit on scroll, we do not honor the CSS
-        // property "background-attachment: fixed" because it may result in rendering
-        // artifacts. Note, these artifacts only appear if we are blitting on scroll of
-        // a page that has fixed background images.
-        fixedAttachment = false;
-    }
-
     if (!fixedAttachment) {
         geometry.setDestRect(snappedPaintRect);
 
         LayoutUnit right = 0;
         LayoutUnit bottom = 0;
         // Scroll and Local.
         if (fillLayer.origin() != BorderFillBox) {
             left = borderLeft();
             right = borderRight();
             top = borderTop();
@@ skipping 1724 matching lines @@
     ASSERT(!beforeChild || toBoxModelObject == beforeChild->parent());
     for (RenderObject* child = slowFirstChild(); child; ) {
         // Save our next sibling as moveChildTo will clear it.
         RenderObject* nextSibling = child->nextSibling();
         moveChildTo(toBoxModelObject, child, beforeChild, fullRemoveInsert);
         child = nextSibling;
     }
 }
 
 } // namespace blink