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

Source/core/rendering/svg/SVGResourcesCycleSolver.h

Index: Source/core/rendering/svg/SVGResourcesCycleSolver.h
diff --git a/Source/core/rendering/svg/SVGResourcesCycleSolver.h b/Source/core/rendering/svg/SVGResourcesCycleSolver.h
index cadaa5a311ebaf08515a0b6995f38c1551bdb88b..2f359d216ceb76e8d3182dc6b1c5b48aa0f84901 100644
--- a/Source/core/rendering/svg/SVGResourcesCycleSolver.h
+++ b/Source/core/rendering/svg/SVGResourcesCycleSolver.h
@@ -38,12 +38,17 @@ public:
     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;
 };
 
 }