Add infrastructure for partial layouts

Source/core/rendering/RenderBlockLineLayout.cpp

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All right reserved.
  * Copyright (C) 2010 Google Inc. 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
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 2150 matching lines @@
             } else if (o->isText() || (o->isRenderInline() && !walker.atEndOfInline())) {
                 if (!o->isText())
                     toRenderInline(o)->updateAlwaysCreateLineBoxes(layoutState.isFullLayout());
                 if (layoutState.isFullLayout() || o->selfNeedsLayout())
                     dirtyLineBoxesForRenderer(o, layoutState.isFullLayout());
                 o->clearNeedsLayout();
             }
         }
 
         for (size_t i = 0; i < replacedChildren.size(); i++)
-             replacedChildren[i]->layoutIfNeeded();
+            replacedChildren[i]->layoutIfNeeded();
 
         layoutRunsAndFloats(layoutState, hasInlineChild);
     }
 
     // Expand the last line to accommodate Ruby and emphasis marks.
     int lastLineAnnotationsAdjustment = 0;
     if (lastRootBox()) {
         LayoutUnit lowestAllowedPosition = max(lastRootBox()->lineBottom(), logicalHeight() + paddingAfter());
         if (!style()->isFlippedLinesWritingMode())
             lastLineAnnotationsAdjustment = lastRootBox()->computeUnderAnnotationAdjustment(lowestAllowedPosition);
@@ skipping 1347 matching lines @@
     lineGridBox->alignBoxesInBlockDirection(logicalHeight(), textBoxDataMap, verticalPositionCache);
 
     setLineGridBox(lineGridBox);
 
     // FIXME: If any of the characteristics of the box change compared to the old one, then we need to do a deep dirtying
     // (similar to what happens when the page height changes). Ideally, though, we only do this if someone is actually snapping
     // to this grid.
 }
 
 }