SkPDF: add `final` keyword to leaf classes

src/pdf/SkPDFFormXObject.h

 
 /*
  * Copyright 2010 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkPDFFormXObject_DEFINED
@@ skipping 12 matching lines @@
 /** \class SkPDFFormXObject
 
     A form XObject; a self contained description of graphics objects.  A form
     XObject is basically a page object with slightly different syntax, that
     can be drawn onto a page.
 */
 
 // The caller could keep track of the form XObjects it creates and
 // canonicalize them, but the Skia API doesn't provide enough context to
 // automatically do it (trivially).
-class SkPDFFormXObject : public SkPDFStream {
+class SkPDFFormXObject final : public SkPDFStream {
 public:
     /** Create a PDF form XObject. Entries for the dictionary entries are
      *  automatically added.
      *  @param device      The set of graphical elements on this form.
      */
     explicit SkPDFFormXObject(SkPDFDevice* device);
     /**
      * Create a PDF form XObject from a raw content stream and associated
      * resources.
      */
     explicit SkPDFFormXObject(SkStream* content,
                               SkRect bbox,
                               SkPDFDict* resourceDict);
     virtual ~SkPDFFormXObject();
 
 private:
     void init(const char* colorSpace,
               SkPDFDict* resourceDict, SkPDFArray* bbox);
 };
 
 #endif