Store repaint rects in the coordinate space of their backing GraphicsLayer.

Source/core/rendering/RenderText.cpp

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Andrew Wellington (proton@wiretapped.net)
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * 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 1602 matching lines @@
     if (startPos == endPos)
         return IntRect();
 
     LayoutRect rect;
     for (InlineTextBox* box = firstTextBox(); box; box = box->nextTextBox()) {
         rect.unite(box->localSelectionRect(startPos, endPos));
         rect.unite(ellipsisRectForBox(box, startPos, endPos));
     }
 
     if (clipToVisibleContent)
-        computeRectForRepaint(repaintContainer, rect);
+        mapRectToRepaintBacking(repaintContainer, rect);
     else {
         if (cb->hasColumns())
             cb->adjustRectForColumns(rect);
 
         rect = localToContainerQuad(FloatRect(rect), repaintContainer).enclosingBoundingBox();
     }
 
     return rect;
 }
 
@@ skipping 234 matching lines @@
     }
     secureTextTimer->restartWithNewText(lastTypedCharacterOffset);
 }
 
 PassRefPtr<AbstractInlineTextBox> RenderText::firstAbstractInlineTextBox()
 {
     return AbstractInlineTextBox::getOrCreate(this, m_firstTextBox);
 }
 
 } // namespace WebCore