Add an SVG DM source

dm/DMSrcSink.h

Index: dm/DMSrcSink.h
diff --git a/dm/DMSrcSink.h b/dm/DMSrcSink.h
index b05fdb0439ba5873b978c06b3cd8f61d1900fd75..a54ddb8d7fb2f0d9f610dc9b9ae5fb0ee88a1dba 100644
--- a/dm/DMSrcSink.h
+++ b/dm/DMSrcSink.h
@@ -248,6 +248,21 @@ private:
     Path fPath;
 };
 
+#if defined(SK_XML)
+class SVGSrc : public Src {
+public:
+    explicit SVGSrc(Path path);
+
+    Error draw(SkCanvas*) const override;
+    SkISize size() const override;
+    Name name() const override;
+
+private:
+    Path fPath;
+
+    typedef Src INHERITED;
+};
+#endif // SK_XML
 /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
 class MSKPSrc : public Src {