Change SkPicture::draw to playback

R=reed@google.com

Author: robertphillips@google.com

Review URL: https://codereview.chromium.org/540963002
diff --git a/gm/gmmain.cpp b/gm/gmmain.cpp
index 5d6481c..40d616e 100644
--- a/gm/gmmain.cpp
+++ b/gm/gmmain.cpp
@@ -633,7 +633,7 @@
                     mat.postTranslate(SkIntToScalar(-xTile*tileSize.width()),
                                       SkIntToScalar(-yTile*tileSize.height()));
                     tileCanvas.setMatrix(mat);
-                    pict->draw(&tileCanvas);
+                    pict->playback(&tileCanvas);
                     tileCanvas.flush();
                     tileCanvas.restoreToCount(saveCount);
                     bmpCanvas.drawBitmap(tileBM,