pdfviewer: add doPage function, cet stream from Contents

experimental/PdfViewer/pdfparser/native/SkNativeParsedPDF.h

 #ifndef EXPERIMENTAL_PDFVIEWER_PDFPARSER_NATIVE_SKNATIVEPARSEDPDF_H_
 #define EXPERIMENTAL_PDFVIEWER_PDFPARSER_NATIVE_SKNATIVEPARSEDPDF_H_
 
 #include "SkRect.h"
 #include "SkTDArray.h"
 
 class SkCanvas;
 
 class SkPdfAllocator;
 class SkPdfMapper;
@@ skipping 36 matching lines @@
     SkPdfResourceDictionary* pageResources(int page);
     SkRect MediaBox(int page);
     SkPdfNativeTokenizer* tokenizerOfPage(int n, SkPdfAllocator* allocator);
 
     SkPdfNativeTokenizer* tokenizerOfStream(SkPdfObject* stream, SkPdfAllocator* allocator);
     SkPdfNativeTokenizer* tokenizerOfBuffer(const unsigned char* buffer, size_t len,
                                             SkPdfAllocator* allocator);
 
     size_t objects() const;
     SkPdfObject* object(int i);
+    SkPdfPageObjectDictionary* page(int page);
 
     const SkPdfMapper* mapper() const;
     SkPdfAllocator* allocator() const;
 
     SkPdfReal* createReal(double value) const;
     SkPdfInteger* createInteger(int value) const;
     // the string does not own the char*
     SkPdfString* createString(const unsigned char* sz, size_t len) const;
 
     SkPdfObject* resolveReference(const SkPdfObject* ref);
@@ skipping 28 matching lines @@
     const unsigned char* fFileContent;
     size_t fContentLength;
     const SkPdfObject* fRootCatalogRef;
     SkPdfCatalogDictionary* fRootCatalog;
 
     mutable SkTDArray<PublicObjectEntry> fObjects;
     SkTDArray<SkPdfPageObjectDictionary*> fPages;
 };
 
 #endif  // EXPERIMENTAL_PDFVIEWER_PDFPARSER_NATIVE_SKNATIVEPARSEDPDF_H_