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

Review URL: https://codereview.chromium.org/1316233002
diff --git a/samplecode/SampleTiling.cpp b/samplecode/SampleTiling.cpp
index 5f995e2..ba79e5a 100644
--- a/samplecode/SampleTiling.cpp
+++ b/samplecode/SampleTiling.cpp
@@ -97,9 +97,9 @@
         SkScalar x = SkIntToScalar(10);
 
         SkPictureRecorder recorder;
-        SkCanvas* textCanvas = NULL;
-        if (NULL == fTextPicture) {
-            textCanvas = recorder.beginRecording(1000, 1000, NULL, 0);
+        SkCanvas* textCanvas = nullptr;
+        if (nullptr == fTextPicture) {
+            textCanvas = recorder.beginRecording(1000, 1000, nullptr, 0);
         }
 
         if (textCanvas) {
@@ -153,7 +153,7 @@
         }
 
         if (textCanvas) {
-            SkASSERT(NULL == fTextPicture);
+            SkASSERT(nullptr == fTextPicture);
             fTextPicture.reset(recorder.endRecording());
         }