Fix the positioning of backgrounds positioned right and bottom

third_party/WebKit/Source/core/paint/BackgroundImageGeometry.cpp

 // Copyright 2014 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 "core/paint/BackgroundImageGeometry.h"
 
 #include "core/frame/FrameView.h"
 #include "core/layout/LayoutBox.h"
 #include "core/layout/LayoutBoxModelObject.h"
 #include "core/layout/LayoutView.h"
@@ skipping 322 matching lines @@
 
         setDestRect(viewportRect);
         positioningAreaSize = destRect().size();
     }
 
     LayoutSize fillTileSize(calculateFillTileSize(positioningBox, fillLayer, positioningAreaSize));
     // It's necessary to apply the heuristic here prior to any further calculations to avoid
     // incorrectly using sub-pixel values that won't be present in the painted tile.
     setTileSize(applySubPixelHeuristicToImageSize(fillTileSize, m_destRect));
 
-    setDestRect(LayoutRect(pixelSnappedIntRect(m_destRect)));
-
-
     EFillRepeat backgroundRepeatX = fillLayer.repeatX();
     EFillRepeat backgroundRepeatY = fillLayer.repeatY();
     LayoutUnit unsnappedAvailableWidth = positioningAreaSize.width() - fillTileSize.width();
     LayoutUnit unsnappedAvailableHeight = positioningAreaSize.height() - fillTileSize.height();
     positioningAreaSize = LayoutSize(snapSizeToPixel(positioningAreaSize.width(), m_destRect.x()), snapSizeToPixel(positioningAreaSize.height(), m_destRect.y()));
     LayoutUnit availableWidth = positioningAreaSize.width() - tileSize().width();
     LayoutUnit availableHeight = positioningAreaSize.height() - tileSize().height();
 
     LayoutUnit computedXPosition = roundedMinimumValueForLength(fillLayer.xPosition(), availableWidth);
     if (backgroundRepeatX == RoundFill && positioningAreaSize.width() > LayoutUnit() && fillTileSize.width() > LayoutUnit()) {
@@ skipping 60 matching lines @@
 
     if (fixedAttachment)
         useFixedAttachment(paintRect.location());
 
     // Clip the final output rect to the paint rect
     m_destRect.intersect(paintRect);
 
     // Snap as-yet unsnapped values.
     DCHECK(m_phase == LayoutPoint(roundedIntPoint(m_phase)));
     setDestRect(LayoutRect(pixelSnappedIntRect(m_destRect)));
-
 }
 
 } // namespace blink