RenderBlock::isSelfCollapsingBlock() should only be used when an object does not require layout.

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 37 matching lines @@
 #include "core/rendering/PaintInfo.h"
 #include "core/rendering/RenderCombineText.h"
 #include "core/rendering/RenderDeprecatedFlexibleBox.h"
 #include "core/rendering/RenderFlexibleBox.h"
 #include "core/rendering/RenderInline.h"
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderMarquee.h"
 #include "core/rendering/RenderNamedFlowThread.h"
 #include "core/rendering/RenderRegion.h"
 #include "core/rendering/RenderTableCell.h"
+#include "core/rendering/RenderTextControl.h"
 #include "core/rendering/RenderTextFragment.h"
 #include "core/rendering/RenderTheme.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/shapes/ShapeOutsideInfo.h"
 #include "core/rendering/style/ContentData.h"
 #include "core/rendering/style/RenderStyle.h"
 #include "platform/geometry/FloatQuad.h"
 #include "platform/geometry/TransformState.h"
 #include "platform/graphics/GraphicsContextStateSaver.h"
 #include "wtf/StdLibExtras.h"
@@ skipping 1072 matching lines @@
                 break;
             }
             setContinuation(0);
             destroy();
         }
     }
 }
 
 bool RenderBlock::isSelfCollapsingBlock() const
 {
-    // FIXME: Add ASSERT(!selfNeedsLayout()) when clearFloatsIfNeeded() and skipLeadingWhitespace() no
-    // longer call here when the block requires layout.
+    ASSERT(!needsLayout());
 
     // We are not self-collapsing if we
     // (a) have a non-zero height according to layout (an optimization to avoid wasting time)
     // (b) are a table,
     // (c) have border/padding,
     // (d) have a min-height
     // (e) have specified that one of our margins can't collapse using a CSS extension
     if (logicalHeight() > 0
         || isTable() || borderAndPaddingLogicalHeight()
         || style()->logicalMinHeight().isPositive()
@@ skipping 4508 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