Repaint squashing content in cases where the entire frame is repainting.

Source/core/rendering/RenderLayerRepainter.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 166 matching lines @@
     for (RenderLayer* child = m_renderer.layer()->firstChild(); child; child = child->nextSibling()) {
         // Don't include repaint rects for composited child layers; they will paint themselves and have a different origin.
         if (child->compositingState() == PaintsIntoOwnBacking || child->compositingState() == PaintsIntoGroupedBacking)
             continue;
 
         repaintRect.unite(child->repainter().repaintRectIncludingNonCompositingDescendants());
     }
     return repaintRect;
 }
 
-void RenderLayerRepainter::setBackingNeedsRepaint()
-{
-    // There is only one call site, and that call site ensures that the compositing state is PaintsIntoOwnBacking.
-    ASSERT(m_renderer.compositingState() == PaintsIntoOwnBacking);
-
-    m_renderer.compositedLayerMapping()->setContentsNeedDisplay();
-}
-
 void RenderLayerRepainter::setBackingNeedsRepaintInRect(const LayoutRect& r)
 {
     // https://bugs.webkit.org/show_bug.cgi?id=61159 describes an unreproducible crash here,
     // so assert but check that the layer is composited.
     ASSERT(m_renderer.compositingState() != NotComposited);
     if (m_renderer.compositingState() == NotComposited) {
         // If we're trying to repaint the placeholder document layer, propagate the
         // repaint to the native view system.
         LayoutRect absRect(r);
         LayoutPoint delta;
@@ skipping 59 matching lines @@
 RenderLayer* RenderLayerRepainter::enclosingFilterRepaintLayer() const
 {
     for (const RenderLayer* curr = m_renderer.layer(); curr; curr = curr->parent()) {
         if ((curr != m_renderer.layer() && curr->requiresFullLayerImageForFilters()) || curr->compositingState() == PaintsIntoOwnBacking || curr->isRootLayer())
             return const_cast<RenderLayer*>(curr);
     }
     return 0;
 }
 
 } // Namespace WebCore