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

Review URL: https://codereview.chromium.org/1316233002
diff --git a/samplecode/SampleManyRects.cpp b/samplecode/SampleManyRects.cpp
index 9c9e985..0290af2 100644
--- a/samplecode/SampleManyRects.cpp
+++ b/samplecode/SampleManyRects.cpp
@@ -65,7 +65,7 @@
             canvas->drawRect(rect, paint);
             canvas->restore();
         }
-        this->inval(NULL);
+        this->inval(nullptr);
     }
 
 private: