hide via-svg until I can fix g3

BUG=skia:

Change-Id: I226194a4db5c9618dd312337bf196d8f21825a12
Reviewed-on: https://skia-review.googlesource.com/8720
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
diff --git a/dm/DMSrcSink.cpp b/dm/DMSrcSink.cpp
index 6e84cc9..e70cae3 100644
--- a/dm/DMSrcSink.cpp
+++ b/dm/DMSrcSink.cpp
@@ -1712,6 +1712,7 @@
 
 /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
+#ifdef TEST_VIA_SVG
 #include "SkXMLWriter.h"
 #include "SkSVGCanvas.h"
 #include "SkSVGDOM.h"
@@ -1734,6 +1735,7 @@
         return "";
     });
 }
+#endif
 
 /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/