pdfviewer: remove dependency on picture_utils. add utility function to render SkStream into bitmap.

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;
 class SkPdfObject;
 class SkPdfReal;
 class SkPdfInteger;
 class SkPdfString;
 class SkPdfResourceDictionary;
 class SkPdfCatalogDictionary;
 class SkPdfPageObjectDictionary;
 class SkPdfPageTreeNodeDictionary;
 
 class SkPdfNativeTokenizer;
 
+class SkStream;
+
 class SkNativeParsedPDF {
 private:
     struct PublicObjectEntry {
         long fOffset;
         // long endOffset;  // TODO(edisonn): determine the end of the object, to be used when the doc is corrupted
         SkPdfObject* fObj;
         // TODO(edisonn): perf ... probably it does not make sense to cache the ref. test it!
         SkPdfObject* fResolvedReference;
     };
 
 public:
     // TODO(edisonn): read methods: file, stream, http(s)://url, url with seek?
     // TODO(edisonn): read first page asap, linearized
     // TODO(edisonn): read page N asap, read all file
     // TODO(edisonn): allow corruptions of file (e.g. missing endobj, missing stream length, ...)
     // TODO(edisonn): encryption
+
     SkNativeParsedPDF(const char* path);
+    SkNativeParsedPDF(SkStream* stream);
+
     ~SkNativeParsedPDF();
 
     int pages() const;
     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);
 
     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);
 
     // Reports an approximation of all the memory usage.
     size_t bytesUsed() const;
 
 private:
 
+    // Takes ownership of bytes.
+    void init(const void* bytes, size_t length);
+
     const unsigned char* readCrossReferenceSection(const unsigned char* xrefStart, const unsigned char* trailerEnd);
     long readTrailer(const unsigned char* trailerStart, const unsigned char* trailerEnd, bool storeCatalog);
 
     // TODO(edisonn): updates not supported right now, generation ignored
     void addCrossSectionInfo(int id, int generation, int offset, bool isFreed);
     static void reset(PublicObjectEntry* obj) {
         obj->fObj = NULL;
         obj->fResolvedReference = NULL;
         obj->fOffset = -1;
     }
 
     SkPdfObject* readObject(int id/*, int generation*/);
 
     void fillPages(SkPdfPageTreeNodeDictionary* tree);
 
     // private fields
     SkPdfAllocator* fAllocator;
     SkPdfMapper* fMapper;
     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_