Style Change: NULL->nullptr
DOCS_PREVIEW= https://skia.org/?cl=1316233002

Review URL: https://codereview.chromium.org/1316233002
diff --git a/gm/picture.cpp b/gm/picture.cpp
index 175e0a7..1f8ded0 100644
--- a/gm/picture.cpp
+++ b/gm/picture.cpp
@@ -40,7 +40,7 @@
 class PictureGM : public skiagm::GM {
 public:
     PictureGM()
-        : fPicture(NULL)
+        : fPicture(nullptr)
     {}
 
 protected:
@@ -65,7 +65,7 @@
         canvas->drawPicture(fPicture);
         
         matrix.setTranslate(110, 0);
-        canvas->drawPicture(fPicture, &matrix, NULL);
+        canvas->drawPicture(fPicture, &matrix, nullptr);
         
         matrix.postTranslate(110, 0);
         canvas->drawPicture(fPicture, &matrix, &paint);