Speculative fix for internal builds

Guard the DMSrcSink SkSVGDOM.h include.

TBR=dogben@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2210583003

Review-Url: https://codereview.chromium.org/2210583003
diff --git a/dm/DMSrcSink.cpp b/dm/DMSrcSink.cpp
index f821616..2e9e565 100644
--- a/dm/DMSrcSink.cpp
+++ b/dm/DMSrcSink.cpp
@@ -34,7 +34,6 @@
 #include "SkSVGCanvas.h"
 #include "SkStream.h"
 #include "SkTLogic.h"
-#include "SkSVGDOM.h"
 #include "SkSwizzler.h"
 #include <functional>
 
@@ -47,6 +46,7 @@
 #endif
 
 #if defined(SK_XML)
+    #include "SkSVGDOM.h"
     #include "SkXMLWriter.h"
 #endif