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

Review URL: https://codereview.chromium.org/1316233002
diff --git a/gm/imageresizetiled.cpp b/gm/imageresizetiled.cpp
index bc640bc..1da2bce 100644
--- a/gm/imageresizetiled.cpp
+++ b/gm/imageresizetiled.cpp
@@ -47,7 +47,7 @@
                 canvas->clipRect(SkRect::MakeXYWH(x, y, tile_size, tile_size));
                 canvas->scale(SkScalarInvert(RESIZE_FACTOR),
                               SkScalarInvert(RESIZE_FACTOR));
-                canvas->saveLayer(NULL, &paint);
+                canvas->saveLayer(nullptr, &paint);
                 const char* str[] = {
                     "The quick",
                     "brown fox",