Clean up transform methods in GraphicsContext.

Source/core/rendering/RenderBox.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. 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
@@ skipping 1109 matching lines @@
 BackgroundBleedAvoidance RenderBox::determineBackgroundBleedAvoidance(GraphicsContext* context) const
 {
     if (context->paintingDisabled())
         return BackgroundBleedNone;
 
     const RenderStyle* style = this->style();
 
     if (!style->hasBackground() || !style->hasBorder() || !style->hasBorderRadius() || canRenderBorderImage())
         return BackgroundBleedNone;
 
+    // FIXME: See crbug.com/382491. getCTM does not accurately reflect the scale at the time content is
+    // rasterized, and should not be relied on to make decisions about bleeding.
     AffineTransform ctm = context->getCTM();
     FloatSize contextScaling(static_cast<float>(ctm.xScale()), static_cast<float>(ctm.yScale()));
 
     // Because RoundedRect uses IntRect internally the inset applied by the
     // BackgroundBleedShrinkBackground strategy cannot be less than one integer
     // layout coordinate, even with subpixel layout enabled. To take that into
     // account, we clamp the contextScaling to 1.0 for the following test so
     // that borderObscuresBackgroundEdge can only return true if the border
     // widths are greater than 2 in both layout coordinates and screen
     // coordinates.
@@ skipping 3555 matching lines @@
         return 0;
 
     if (!layoutState && !flowThreadContainingBlock())
         return 0;
 
     RenderBlock* containerBlock = containingBlock();
     return containerBlock->offsetFromLogicalTopOfFirstPage() + logicalTop();
 }
 
 } // namespace WebCore