Update sprint to graphite name

Change-Id: Ice0826af0b64fa8dd92975f879af8ab0f71740fc
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/451039
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
diff --git a/dm/DMSrcSink.h b/dm/DMSrcSink.h
index 30245f0..565cb31 100644
--- a/dm/DMSrcSink.h
+++ b/dm/DMSrcSink.h
@@ -579,12 +579,12 @@
     int fPageIndex;
 };
 
-class TBDSink : public Sink {
+class GraphiteSink : public Sink {
 public:
-    TBDSink();
+    GraphiteSink();
 
     Result draw(const Src&, SkBitmap*, SkWStream*, SkString*) const override;
-    const char* fileExtension() const override { return "tbd"; }
+    const char* fileExtension() const override { return "gr"; }
     SinkFlags flags() const override { return SinkFlags{ SinkFlags::kVector, SinkFlags::kDirect }; }
 };