Removed NativeMetafile and PreviewMetafile typedef as it's always PdfMetafileSkia.

printing/printing_context_win.cc

Index: printing/printing_context_win.cc
diff --git a/printing/printing_context_win.cc b/printing/printing_context_win.cc
index 4d7ea92b1cc9c6cce06b1ef6a590b64fda082501..3e4e6e9396e1dd8a7355285791ae9cfbf5b26b9b 100644
--- a/printing/printing_context_win.cc
+++ b/printing/printing_context_win.cc
@@ -284,7 +284,7 @@ PrintingContext::Result PrintingContextWin::NewPage() {
   DCHECK(context_);
   DCHECK(in_print_job_);
 
-  // Intentional No-op. NativeMetafile::SafePlayback takes care of calling
+  // Intentional No-op. PdfMetafileSkia::SafePlayback takes care of calling
   // ::StartPage().
 
   return OK;
@@ -295,7 +295,7 @@ PrintingContext::Result PrintingContextWin::PageDone() {
     return CANCEL;
   DCHECK(in_print_job_);
 
-  // Intentional No-op. NativeMetafile::SafePlayback takes care of calling
+  // Intentional No-op. PdfMetafileSkia::SafePlayback takes care of calling
   // ::EndPage().
 
   return OK;