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

Review URL: https://codereview.chromium.org/1316233002
diff --git a/samplecode/SampleLines.cpp b/samplecode/SampleLines.cpp
index 0166bc0..4570635 100644
--- a/samplecode/SampleLines.cpp
+++ b/samplecode/SampleLines.cpp
@@ -65,7 +65,7 @@
     void onDrawContent(SkCanvas* canvas) override {
         SkBitmap bm;
         SkImageDecoder::DecodeFile("/kill.gif", &bm);
-        canvas->drawBitmap(bm, 0, 0, NULL);
+        canvas->drawBitmap(bm, 0, 0, nullptr);
 
         this->drawRings(canvas);
         return;
@@ -98,8 +98,8 @@
 
     SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned) override {
         fAlpha = SkScalarRoundToInt(y);
-        this->inval(NULL);
-        return NULL;
+        this->inval(nullptr);
+        return nullptr;
     }
 private: