[SVGDom] Improved DM sizing

dm/DMSrcSink.h

Index: dm/DMSrcSink.h
diff --git a/dm/DMSrcSink.h b/dm/DMSrcSink.h
index dfc4955b5a03da4e5f00adcfa9931eca4bae1afc..e8466aa50d45c3846d92c67f6f4f64e324eba0f7 100644
--- a/dm/DMSrcSink.h
+++ b/dm/DMSrcSink.h
@@ -249,6 +249,12 @@ private:
 };
 
 #if defined(SK_XML)
+} // namespace DM
+
+class SkSVGDOM;
+
+namespace DM {
+
 class SVGSrc : public Src {
 public:
     explicit SVGSrc(Path path);
@@ -259,7 +265,11 @@ public:
     bool veto(SinkFlags) const override;
 
 private:
-    Path fPath;
+    Error ensureDom() const;
+
+    Path                    fPath;
+    mutable sk_sp<SkSVGDOM> fDom;
+    mutable SkScalar        fScale;
 
     typedef Src INHERITED;
 };