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

Review URL: https://codereview.chromium.org/1316233002
diff --git a/gm/colortypexfermode.cpp b/gm/colortypexfermode.cpp
index 2926523..55d7697 100644
--- a/gm/colortypexfermode.cpp
+++ b/gm/colortypexfermode.cpp
@@ -20,7 +20,7 @@
     const static int W = 64;
     const static int H = 64;
     ColorTypeXfermodeGM()
-        : fColorType(NULL) {
+        : fColorType(nullptr) {
     }
 
     virtual ~ColorTypeXfermodeGM() {
@@ -35,7 +35,7 @@
         };
         SkMatrix local;
         local.setRotate(180);
-        SkShader* s = SkGradientShader::CreateSweep(0,0, colors, NULL,
+        SkShader* s = SkGradientShader::CreateSweep(0,0, colors, nullptr,
                                                     SK_ARRAY_COUNT(colors), 0, &local);
 
         SkPaint paint;
@@ -44,7 +44,7 @@
 
         SkTypeface* orig = sk_tool_utils::create_portable_typeface("serif",
                                                             SkTypeface::kBold);
-        if (NULL == orig) {
+        if (nullptr == orig) {
             orig = SkTypeface::RefDefault();
         }
         fColorType = new SkGTypeface(orig, paint);
@@ -138,7 +138,7 @@
 
             r.inset(-SK_ScalarHalf, -SK_ScalarHalf);
             p.setStyle(SkPaint::kStroke_Style);
-            p.setShader(NULL);
+            p.setShader(nullptr);
             canvas->drawRect(r, p);
 
             textP.setXfermode(mode);