Invalidate the frame view when changing the background image of the document or body.

Source/core/rendering/RenderBox.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, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. 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 1265 matching lines @@
 bool RenderBox::paintInvalidationLayerRectsForImage(WrappedImagePtr image, const FillLayer& layers, bool drawingBackground)
 {
     Vector<RenderObject*> layerRenderers;
 
     // A background of the body or document must extend to the total visible size of the document. This means the union of the
     // view and document bounds, since it can be the case that the view is larger than the document and vice-versa.
     // http://dev.w3.org/csswg/css-backgrounds/#the-background
     if (drawingBackground && (isDocumentElement() || (isBody() && !document().documentElement()->renderer()->hasBackground()))) {
         layerRenderers.append(document().documentElement()->renderer());
         layerRenderers.append(view());
+        if (view()->frameView())
+            view()->frameView()->setNeedsFullPaintInvalidation();

[dsinclair, 2014/10/31 00:14:34]

What about doing view()->setShouldDoFullPaintInvalidation() which should force
the render view to fully invalidate? Then you don't need to add
setNeedsFullPaintInvalidation on frameView.

[Xianzhu, 2014/10/31 16:37:30]

Would view()->setNeedsFullPaintInvalidation() work?

     } else {
         layerRenderers.append(this);
     }
     for (const FillLayer* curLayer = &layers; curLayer; curLayer = curLayer->next()) {
         if (curLayer->image() && image == curLayer->image()->data() && curLayer->image()->canRender(*this, style()->effectiveZoom())) {
             for (RenderObject* layerRenderer : layerRenderers)
                 layerRenderer->setShouldDoFullPaintInvalidation();
             return true;
         }
     }
@@ skipping 3131 matching lines @@
 
     setLogicalTop(oldLogicalTop);
     setLogicalWidth(oldLogicalWidth);
     setMarginLeft(oldMarginLeft);
     setMarginRight(oldMarginRight);
 
     return borderBox;
 }
 
 } // namespace blink