Remove the SVG paint culling optimization

Source/core/rendering/svg/RenderSVGBlock.cpp

 /*
  * Copyright (C) 2006 Apple Computer, Inc.
  * 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 108 matching lines @@
 {
     ASSERT_NOT_REACHED();
     return false;
 }
 
 void RenderSVGBlock::invalidateTreeIfNeeded(const PaintInvalidationState& paintInvalidationState)
 {
     if (!shouldCheckForPaintInvalidation(paintInvalidationState))
         return;
 
+    if (paintInvalidationState.cachedOffsetsEnabled())
+        m_cachedPaintInvalidationTransform = paintInvalidationState.svgTransform();

[fs, 2014/12/17 10:16:10]

I think you need an else-branch here which calls the method from one of the
older PS's (to compute this the slow and arduous way). This is needed because of
the ForceHorriblySlowRectMapping below, and I think a case like:

<svg>
  <foreignObject>
    <svg>
      <text>

could trigger it.

[pdr., 2014/12/18 22:22:41]

Took a while to create a testcase but you were absolutely right. Fixed, and
added a test to prove it.

+
     ForceHorriblySlowRectMapping slowRectMapping(&paintInvalidationState);
     RenderBlockFlow::invalidateTreeIfNeeded(paintInvalidationState);
 }
 
 }