Suppress layer creation for descendants of GPU-rasterized layers

Source/core/rendering/RenderBlock.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. 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
  * License as published by the Free Software Foundation; either
@@ skipping 212 matching lines @@
     if (hasColumns())
         gColumnInfoMap->take(this);
     if (gPercentHeightDescendantsMap)
         removeBlockFromDescendantAndContainerMaps(this, gPercentHeightDescendantsMap, gPercentHeightContainerMap);
     if (gPositionedDescendantsMap)
         removeBlockFromDescendantAndContainerMaps(this, gPositionedDescendantsMap, gPositionedContainerMap);
 }
 
 void RenderBlock::willBeDestroyed()
 {
+    // Hits in compositing/squashing/squash-onto-nephew.html.
+    DisableCompositingQueryAsserts disabler;

[abarth-chromium, 2014/04/17 17:29:51]

Where is the access to composited state?  I don't see it here.

[ajuma, 2014/04/17 19:24:44]

It's actually in ~CompositedLayerMapping(). I've moved the disabler there.

+
     // Mark as being destroyed to avoid trouble with merges in removeChild().
     m_beingDestroyed = true;
 
     // Make sure to destroy anonymous children first while they are still connected to the rest of the tree, so that they will
     // properly dirty line boxes that they are removed from. Effects that do :before/:after only on hover could crash otherwise.
     children()->destroyLeftoverChildren();
 
     // Destroy our continuation before anything other than anonymous children.
     // The reason we don't destroy it before anonymous children is that they may
     // have continuations of their own that are anonymous children of our continuation.
@@ skipping 4664 matching lines @@
 void RenderBlock::showLineTreeAndMark(const InlineBox* markedBox1, const char* markedLabel1, const InlineBox* markedBox2, const char* markedLabel2, const RenderObject* obj) const
 {
     showRenderObject();
     for (const RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox())
         root->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, 1);
 }
 
 #endif
 
 } // namespace WebCore