Remove assorted dead paint invalidation code.

sky/engine/core/rendering/RenderLayer.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 1931 matching lines @@
         // We can optimize away code paths in other places if we know that there are no software filters.
         renderer()->document().view()->setHasSoftwareFilters(true);
     }
 
     // If the filter fails to build, remove it from the layer. It will still attempt to
     // go through regular processing (e.g. compositing), but never apply anything.
     if (!filterInfo->renderer()->build(renderer(), computeFilterOperations(renderer()->style())))
         filterInfo->setRenderer(nullptr);
 }
 
-void RenderLayer::filterNeedsPaintInvalidation()
-{
-}
-
 } // namespace blink
 
 #ifndef NDEBUG
 void showLayerTree(const blink::RenderLayer* layer)
 {
     if (!layer)
         return;
 
     if (blink::LocalFrame* frame = layer->renderer()->frame()) {
         WTF::String output = externalRepresentation(frame, blink::RenderAsTextShowAllLayers | blink::RenderAsTextShowLayerNesting | blink::RenderAsTextShowCompositedLayers | blink::RenderAsTextShowAddresses | blink::RenderAsTextShowIDAndClass | blink::RenderAsTextDontUpdateLayout | blink::RenderAsTextShowLayoutState);
         fprintf(stderr, "%s\n", output.utf8().data());
     }
 }
 
 void showLayerTree(const blink::RenderObject* renderer)
 {
     if (!renderer)
         return;
     showLayerTree(renderer->enclosingLayer());
 }
 #endif