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

Review URL: https://codereview.chromium.org/1316233002
diff --git a/samplecode/SampleAARectModes.cpp b/samplecode/SampleAARectModes.cpp
index f9972ae..ae28925 100644
--- a/samplecode/SampleAARectModes.cpp
+++ b/samplecode/SampleAARectModes.cpp
@@ -112,7 +112,7 @@
                 SkXfermode* mode = SkXfermode::Create(gModes[i].fMode);
 
                 canvas->drawRect(bounds, fBGPaint);
-                canvas->saveLayer(&bounds, NULL);
+                canvas->saveLayer(&bounds, nullptr);
                 SkScalar dy = drawCell(canvas, mode,
                                        gAlphaValue[alpha & 1],
                                        gAlphaValue[alpha & 2]);