SkPDF: add `final` keyword to leaf classes

src/pdf/SkPDFBitmap.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 "SkColorPriv.h"
 #include "SkData.h"
 #include "SkDeflate.h"
@@ skipping 362 matching lines @@
 
     pdf_stream_begin(stream);
     stream->writeStream(asset.get(), asset->getLength());
     pdf_stream_end(stream);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
 namespace {
 // This SkPDFObject only outputs the alpha layer of the given bitmap.
-class PDFAlphaBitmap : public SkPDFObject {
+class PDFAlphaBitmap final : public SkPDFObject {
 public:
     PDFAlphaBitmap(const SkImage* image) : fImage(SkRef(image)) {}
     ~PDFAlphaBitmap() {}
     void emitObject(SkWStream*  stream,
                     const SkPDFObjNumMap& objNumMap,
                     const SkPDFSubstituteMap& subs) const override {
         emit_image_xobject(stream, fImage, true, nullptr, objNumMap, subs);
     }
 
 private:
     SkAutoTUnref<const SkImage> fImage;
 };
 
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 
 namespace {
-class PDFDefaultBitmap : public SkPDFObject {
+class PDFDefaultBitmap final : public SkPDFObject {
 public:
     void emitObject(SkWStream* stream,
                     const SkPDFObjNumMap& objNumMap,
                     const SkPDFSubstituteMap& subs) const override {
         emit_image_xobject(stream, fImage, false, fSMask, objNumMap, subs);
     }
     void addResources(SkPDFObjNumMap* catalog,
                       const SkPDFSubstituteMap& subs) const override {
         if (fSMask.get()) {
             SkPDFObject* obj = subs.getSubstitute(fSMask.get());
@@ skipping 11 matching lines @@
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 
 namespace {
 /**
  *  This PDFObject assumes that its constructor was handed YUV or
  *  Grayscale JFIF Jpeg-encoded data that can be directly embedded
  *  into a PDF.
  */
-class PDFJpegBitmap : public SkPDFObject {
+class PDFJpegBitmap final : public SkPDFObject {
 public:
     SkISize fSize;
     SkAutoTUnref<SkData> fData;
     bool fIsYUV;
     PDFJpegBitmap(SkISize size, SkData* data, bool isYUV)
         : fSize(size), fData(SkRef(data)), fIsYUV(isYUV) {}
     void emitObject(SkWStream*,
                     const SkPDFObjNumMap&,
                     const SkPDFSubstituteMap&) const override;
 };
@@ skipping 36 matching lines @@
             return new PDFJpegBitmap(info.fSize, data, yuv);
         }
     }
     SkPDFObject* smask =
             image_compute_is_opaque(image) ? nullptr : new PDFAlphaBitmap(image);
     #ifdef SK_PDF_IMAGE_STATS
     gRegularImageObjects.fetch_add(1);
     #endif
     return new PDFDefaultBitmap(image, smask);
 }