SkDocument/PDF: new API

src/pdf/SkDocument_PDF_None.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkDocument.h"
-SkDocument* SkDocument::CreatePDF(SkWStream*, SkScalar) { return  nullptr; }
-SkDocument* SkDocument::CreatePDF(const char path[], SkScalar) { return nullptr; }
+sk_sp<SkDocument> SkDocument::MakePDF(SkWStream*,
+                                      SkScalar,
+                                      const SkDocument::PDFMetadata&,
+                                      SkPixelSerializer*,
+                                      bool) {
+    return nullptr;
+}
+sk_sp<SkDocument> SkDocument::MakePDF(const char path[], SkScalar) {
+    return nullptr;
+}