Have SVGURIReference API deal with Document references, not pointers

Source/core/svg/graphics/filters/SVGFEImage.h

Index: Source/core/svg/graphics/filters/SVGFEImage.h
diff --git a/Source/core/svg/graphics/filters/SVGFEImage.h b/Source/core/svg/graphics/filters/SVGFEImage.h
index 1566b7ad6cf81106020b91185352434f1ead3ce8..3f755418bad36241fc813cffb69b1e62e2bee6a5 100644
--- a/Source/core/svg/graphics/filters/SVGFEImage.h
+++ b/Source/core/svg/graphics/filters/SVGFEImage.h
@@ -36,7 +36,7 @@ class RenderObject;
 class FEImage : public FilterEffect {
 public:
     static PassRefPtr<FEImage> createWithImage(Filter*, PassRefPtr<Image>, const SVGPreserveAspectRatio&);
-    static PassRefPtr<FEImage> createWithIRIReference(Filter*, Document*, const String&, const SVGPreserveAspectRatio&);
+    static PassRefPtr<FEImage> createWithIRIReference(Filter*, Document&, const String&, const SVGPreserveAspectRatio&);
 
     virtual void determineAbsolutePaintRect();
 
@@ -48,7 +48,7 @@ public:
 private:
     virtual ~FEImage() { }
     FEImage(Filter*, PassRefPtr<Image>, const SVGPreserveAspectRatio&);
-    FEImage(Filter*, Document*, const String&, const SVGPreserveAspectRatio&);
+    FEImage(Filter*, Document&, const String&, const SVGPreserveAspectRatio&);
     RenderObject* referencedRenderer() const;
 
     virtual void applySoftware() OVERRIDE;