Extract the SVG Filter Reference implementation out of the FilterEffectRenderer into its own type

Source/core/platform/graphics/filters/ReferenceFilter.h

Index: Source/core/platform/graphics/filters/ReferenceFilter.h
diff --git a/Source/core/rendering/style/StyleCustomFilterProgram.cpp b/Source/core/platform/graphics/filters/ReferenceFilter.h
similarity index 61%
copy from Source/core/rendering/style/StyleCustomFilterProgram.cpp
copy to Source/core/platform/graphics/filters/ReferenceFilter.h
index 31c3d64d662ce7da9ff0582f323a1c6c79d0fe36..7bc87dcc4b380abc71299863b480b24d2a081ea3 100644
--- a/Source/core/rendering/style/StyleCustomFilterProgram.cpp
+++ b/Source/core/platform/graphics/filters/ReferenceFilter.h
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
+ * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -27,20 +28,41 @@
  * SUCH DAMAGE.
  */
 
-#include "config.h"
+#ifndef ReferenceFilter_h
+#define ReferenceFilter_h
 
-#include "core/rendering/style/StyleCustomFilterProgram.h"
-
-#include "core/rendering/style/StyleCustomFilterProgramCache.h"
+#include "core/platform/graphics/FloatRect.h"
+#include "core/platform/graphics/filters/Filter.h"
+#include "wtf/PassRefPtr.h"
+#include "wtf/RefPtr.h"
 
 namespace WebCore {
 
-StyleCustomFilterProgram::~StyleCustomFilterProgram()
-{
-    if (m_cache)
-        m_cache->remove(this);
-}
+class SourceGraphic;
+class FilterEffect;
+
+class ReferenceFilter: public Filter {
+public:
+    static PassRefPtr<ReferenceFilter> create()
+    {
+        return adoptRef(new ReferenceFilter());
+    }
+
+    virtual FloatRect sourceImageRect() const { return FloatRect(); };
 
-} // namespace WebCore
+    void setLastEffect(PassRefPtr<FilterEffect>);
+    FilterEffect* lastEffect() const { return m_lastEffect.get(); }
 
+    SourceGraphic* sourceGraphic() const { return m_sourceGraphic.get(); }
+
+private:
+    ReferenceFilter();
+    ~ReferenceFilter();
+
+    RefPtr<SourceGraphic> m_sourceGraphic;
+    RefPtr<FilterEffect> m_lastEffect;
+};
+
+}
 
+#endif // ReferenceFilter_h