Push selection gaps logic down to RenderBlockFlow

Source/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 2138 matching lines @@
             rect.intersect(box->overflowClipRect(LayoutPoint()));
     }
     if (renderer()->hasClip())
         rect.intersect(toRenderBox(renderer())->clipRect(LayoutPoint()));
     if (!rect.isEmpty())
         renderer()->invalidatePaintRectangle(rect);
 }
 
 IntRect RenderLayer::blockSelectionGapsBounds() const
 {
-    if (!renderer()->isRenderBlock())
+    if (!renderer()->isRenderBlockFlow())
         return IntRect();
 
-    RenderBlock* renderBlock = toRenderBlock(renderer());
-    LayoutRect gapRects = renderBlock->selectionGapRectsForPaintInvalidation(renderBlock);
+    RenderBlockFlow* renderBlockFlow = toRenderBlockFlow(renderer());
+    LayoutRect gapRects = renderBlockFlow->selectionGapRectsForPaintInvalidation(renderBlockFlow);
 
     return pixelSnappedIntRect(gapRects);
 }
 
 bool RenderLayer::hasBlockSelectionGapBounds() const
 {
     // FIXME: it would be more accurate to return !blockSelectionGapsBounds().isEmpty(), but this is impossible
     // at the moment because it causes invalid queries to layout-dependent code (crbug.com/372802).
     // ASSERT(renderer()->document().lifecycle().state() >= DocumentLifecycle::LayoutClean);
 
@@ skipping 666 matching lines @@
     }
 }
 
 void showLayerTree(const blink::RenderObject* renderer)
 {
     if (!renderer)
         return;
     showLayerTree(renderer->enclosingLayer());
 }
 #endif