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

Review URL: https://codereview.chromium.org/1316233002
diff --git a/gm/pathopsskpclip.cpp b/gm/pathopsskpclip.cpp
index c9092f4..1c8cf99 100644
--- a/gm/pathopsskpclip.cpp
+++ b/gm/pathopsskpclip.cpp
@@ -34,7 +34,7 @@
 
     void onDraw(SkCanvas* canvas) override {
         SkPictureRecorder recorder;
-        SkCanvas* rec = recorder.beginRecording(1200, 900, NULL, 0);
+        SkCanvas* rec = recorder.beginRecording(1200, 900, nullptr, 0);
         SkPath p;
         SkRect r = {
             SkIntToScalar(100),