Fix DM race in SVGSrc

dm/DMSrcSink.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef DMSrcSink_DEFINED
 #define DMSrcSink_DEFINED
 
@@ skipping 243 matching lines @@
 class SVGSrc : public Src {
 public:
     explicit SVGSrc(Path path);
 
     Error draw(SkCanvas*) const override;
     SkISize size() const override;
     Name name() const override;
     bool veto(SinkFlags) const override;
 
 private:
-    Error ensureDom() const;
-
-    Path                    fPath;
-    mutable sk_sp<SkSVGDOM> fDom;
-    mutable SkScalar        fScale;
+    Name            fName;
+    sk_sp<SkSVGDOM> fDom;
+    SkScalar        fScale;
 
     typedef Src INHERITED;
 };
 #endif // SK_XML
 /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
 class MSKPSrc : public Src {
 public:
     explicit MSKPSrc(Path path);
 
@@ skipping 198 matching lines @@
 
 class ViaLite : public Via {
 public:
     explicit ViaLite(Sink* sink) : Via(sink) {}
     Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const override;
 };
 
 }  // namespace DM
 
 #endif//DMSrcSink_DEFINED