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

Review URL: https://codereview.chromium.org/1316233002
diff --git a/gm/convexpolyclip.cpp b/gm/convexpolyclip.cpp
index 2aa05a8..fbfd167 100644
--- a/gm/convexpolyclip.cpp
+++ b/gm/convexpolyclip.cpp
@@ -169,7 +169,7 @@
                         clip->getBounds(&bounds);
                         bounds.outset(2, 2);
                         bounds.offset(x, y);
-                        canvas->saveLayer(&bounds, NULL);
+                        canvas->saveLayer(&bounds, nullptr);
                     } else {
                         canvas->save();
                     }
@@ -192,7 +192,7 @@
                         clip->getBounds(&bounds);
                         bounds.outset(2, 2);
                         bounds.offset(x, y);
-                        canvas->saveLayer(&bounds, NULL);
+                        canvas->saveLayer(&bounds, nullptr);
                     } else {
                         canvas->save();
                     }