Style Change: NULL->nullptr

site/dev/testing/fonts.md

 Fonts and GM Tests
 ==================
 
 Overview
 --------
 
 Each test in the gm directory draws a reference image. Their primary purpose is
 to detect when images change unexpectedly, indicating that a rendering bug has
 been introduced.
 
@@ skipping 52 matching lines @@
 invoked.
 
 
 GM font selection
 -----------------
 
 Each gm specifies the typeface to use when drawing text. For now, to set the
 portable typeface on the paint, call:
 
 ~~~~
-sk_tool_utils::set_portable_typeface(SkPaint* , const char* name = NULL,
+sk_tool_utils::set_portable_typeface(SkPaint* , const char* name = nullptr,
 SkTypeface::Style style = SkTypeface::kNormal );
 ~~~~
 
 To create a portable typeface, use:
 
 ~~~~
 SkTypeface* typeface = sk_tool_utils::create_portable_typeface(const char* name,
 SkTypeface::Style style);
 ~~~~
 
@@ skipping 25 matching lines @@
 
 Adding support for selecting from multiple font managers at runtime permits
 removing manual typeface selection in the gm tests. Today, options to dm like
 '\-\-pipe' fail with '\-\-portableFonts' because we're hard-coded to using the default
 font manage when pictures are serialized.
 
 Some gm tests explicitly always want to use system fonts and system metrics;
 other gm tests use text only to label the drawing; yet other gm tests use text
 to generate paths for testing. Additional discrimination is needed to
 distinguish these cases.