Make SVGResourcesCycleSolver check for cycles beyond one level (and more)

Source/core/rendering/svg/SVGResourcesCycleSolver.h

 /*
  * 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.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 20 matching lines @@
 
 class SVGResourcesCycleSolver {
     WTF_MAKE_NONCOPYABLE(SVGResourcesCycleSolver);
 public:
     SVGResourcesCycleSolver(RenderObject*, SVGResources*);
     ~SVGResourcesCycleSolver();
 
     void resolveCycles();
 
 private:
-    bool resourceContainsCycles(RenderObject*) const;
+    bool resourceContainsCycles(RenderSVGResourceContainer*);

[krit, 2014/05/28 10:22:30]

Are all renderers that we ever want to track are SVG ResourceContainers? I am
more thinking into the future here. At the moment this is probably correct. We
just have SVG gradients, patterns, filters, clip path, markers, masks.

[fs, 2014/05/28 11:23:48]

Did you have anything in particular predicted for the future? =)

I think this makes sense in the current scope and usage of things. Generalizing
wouldn't be hard though I think, but preferably that's something to do when it's
actually needed. (And after all, this is the SVG_Resource_CycleSolver ;-))

     void breakCycle(RenderSVGResourceContainer*);
 
+    class ActiveFrame;

[krit, 2014/05/28 10:22:30]

Does that need to be a class? If it is private, a simple struct seems to do it.

[fs, 2014/05/28 11:23:48]

I guess I instinctively make things class:es when nothing else needs to access
it's data members.

+
     RenderObject* m_renderer;
     SVGResources* m_resources;
-    HashSet<RenderSVGResourceContainer*> m_allResources;
+
+    typedef HashSet<RenderSVGResourceContainer*> ResourceSet;
+    ResourceSet m_activeResources;
+    ResourceSet m_dagCache;
 };
 
 }
 
 #endif