Calculate correct clip foregroundBound and backgroundBound

Source/core/paint/DeprecatedPaintLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 1365 matching lines @@
     clipper().calculateRects(clipRectsContext, dirtyRect, fragment.layerBounds, fragment.backgroundRect, fragment.foregroundRect, fragment.outlineRect, offsetFromRoot);
     fragments.append(fragment);
 }
 
 void DeprecatedPaintLayer::collectFragments(DeprecatedPaintLayerFragments& fragments, const DeprecatedPaintLayer* rootLayer, const LayoutRect& dirtyRect,
     ClipRectsCacheSlot clipRectsCacheSlot, OverlayScrollbarSizeRelevancy inOverlayScrollbarSizeRelevancy, ShouldRespectOverflowClip respectOverflowClip, const LayoutPoint* offsetFromRoot,
     const LayoutSize& subPixelAccumulation, const LayoutRect* layerBoundingBox)
 {
     if (!enclosingPaginationLayer()) {
         // For unpaginated layers, there is only one fragment.
-        appendSingleFragmentIgnoringPagination(fragments, rootLayer, dirtyRect, clipRectsCacheSlot, inOverlayScrollbarSizeRelevancy, respectOverflowClip, offsetFromRoot, subPixelAccumulation);
+        const LayoutSize subPixelAccumulationIfNeeded = compositingState() == PaintsIntoOwnBacking ? LayoutSize() : subPixelAccumulation;
+        appendSingleFragmentIgnoringPagination(fragments, rootLayer, dirtyRect, clipRectsCacheSlot, inOverlayScrollbarSizeRelevancy, respectOverflowClip, offsetFromRoot, subPixelAccumulationIfNeeded);
         return;
     }
 
     // Compute our offset within the enclosing pagination layer.
     LayoutPoint offsetWithinPaginatedLayer;
     convertToLayerCoords(enclosingPaginationLayer(), offsetWithinPaginatedLayer);
 
     // Calculate clip rects relative to the enclosingPaginationLayer. The purpose of this call is to determine our bounds clipped to intermediate
     // layers between us and the pagination context. It's important to minimize the number of fragments we need to create and this helps with that.
     ClipRectsContext paginationClipRectsContext(enclosingPaginationLayer(), clipRectsCacheSlot, inOverlayScrollbarSizeRelevancy);
@@ skipping 1257 matching lines @@
 
 void showLayerTree(const blink::LayoutObject* layoutObject)
 {
     if (!layoutObject) {
         fprintf(stderr, "Cannot showLayerTree. Root is (nil)\n");
         return;
     }
     showLayerTree(layoutObject->enclosingLayer());
 }
 #endif