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

Review URL: https://codereview.chromium.org/1316233002
diff --git a/src/views/SkTagList.h b/src/views/SkTagList.h
index 47294e3..1cff9ca 100644
--- a/src/views/SkTagList.h
+++ b/src/views/SkTagList.h
@@ -29,7 +29,7 @@
     SkTagList(U8CPU tag) : fTag(SkToU8(tag))
     {
         SkASSERT(tag < kSkTagListCount);
-        fNext       = NULL;
+        fNext       = nullptr;
         fExtra16    = 0;
         fExtra8     = 0;
     }