add portable and canonical font support for DM

gm/imagemagnifier.cpp

Index: gm/imagemagnifier.cpp
diff --git a/gm/imagemagnifier.cpp b/gm/imagemagnifier.cpp
index 23847e6f1539dbd305eec74522acaa882063496d..e2847b4c67312707b5aa1110a3b87986702a877a 100644
--- a/gm/imagemagnifier.cpp
+++ b/gm/imagemagnifier.cpp
@@ -44,6 +44,7 @@ protected:
                 100))->unref();
         canvas->saveLayer(NULL, &paint);
         paint.setAntiAlias(true);
+        sk_tool_utils::set_portable_typeface(&paint);
         const char* str = "The quick brown fox jumped over the lazy dog.";
         SkRandom rand;
         for (int i = 0; i < 25; ++i) {