Track the region where text is painted.

Source/core/rendering/svg/SVGInlineTextBox.cpp

 /**
  * Copyright (C) 2007 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * 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
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 600 matching lines @@
         if (!prepareGraphicsContextForTextPainting(context, scalingFactor, textRun, style))
             break;
 
         FloatSize extraOffset;
         if (shadow)
             extraOffset = applyShadowToGraphicsContext(context, shadow, shadowRect, false /* stroked */, true /* opaque */, true /* horizontal */);
 
         context->save();
         context->scale(FloatSize(1 / scalingFactor, 1 / scalingFactor));
 
-        scaledFont.drawText(context, textRun, textOrigin + extraOffset, startPosition, endPosition);
+        scaledFont.drawText(context, textRun, textOrigin + extraOffset, FloatRect(textOrigin, textSize), startPosition, endPosition);
 
         context->restore();
 
         restoreGraphicsContextAfterTextPainting(context, textRun);
 
         if (!shadow)
             break;
 
         if (shadow->next())
             context->restore();
@@ skipping 88 matching lines @@
                     return true;
              }
         }
     }
     return false;
 }
 
 } // namespace WebCore
 
 #endif