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

Review URL: https://codereview.chromium.org/1316233002
diff --git a/tests/SkBase64Test.cpp b/tests/SkBase64Test.cpp
index a534768..d855ef5 100644
--- a/tests/SkBase64Test.cpp
+++ b/tests/SkBase64Test.cpp
@@ -17,7 +17,7 @@
 
     for (int offset = 0; offset < 6; ++offset) {
         size_t length = 256 - offset;
-        size_t encodeLength = SkBase64::Encode(all + offset, length, NULL);
+        size_t encodeLength = SkBase64::Encode(all + offset, length, nullptr);
         SkAutoTMalloc<char> src(encodeLength + 1);
         SkBase64::Encode(all + offset, length, src.get());
         src[SkToInt(encodeLength)] = '\0';